diff --git a/config/default.cfg b/config/default.cfg
index f2be8a9e02..1215b59e0a 100644
--- a/config/default.cfg
+++ b/config/default.cfg
@@ -574,7 +574,7 @@ cfg$gms$c17_prod_init <- "on"         # default = on
 # ***---------------------    18_residues    -----------------------------------
 # * (flexreg_apr16): detailed residue calculations
 # * (off): off
-cfg$gms$residues <- "flexreg_apr16"            # def = flexreg_apr16
+cfg$gms$residues <- "disaggRes_apr25"            # def = flexreg_apr16
 
 # * residue on field burning
 # * options:   phaseout - phaseout of residue burning to minimum burn share (0-10%)
@@ -1827,6 +1827,7 @@ cfg$gms$s58_fix_peatland  <- 2020   # def = 2020
 # * (static_jan19): static soil carbon loss for cropland
 # * (cellpool_jan23): dynamic soil organic matter pool on cellular level
 # *                   with updated, regionalized stock change factors (IPCC guidelines 2019)
+# cfg$gms$som <- "threepool_may23"
 cfg$gms$som <- "cellpool_jan23"    # def = cellpool_jan23
 
 # * static realization switch
@@ -2177,7 +2178,12 @@ cfg$gms$c80_nlp_solver <- "conopt4"              # def = conopt4
 
 # * 1: using optfile for specified solver settings
 # * 0: default settings (optfile will be ignored)
-cfg$gms$s80_optfile <- 0 # def = 0
+cfg$gms$s80_optfile <- 1 # def = 1
+
+# Solver setting Tol_Optimality (real): 
+# Optimality tolerance for reduced gradient when feasible.
+# Range: [3.e-13, 1], Solver default: 1.e-7
+cfg$gms$s80_toloptimal <- 1.0e-8 # def = 1.0e-8
 
 # * Optional second solve statement (0=off, 1=on)
 cfg$gms$s80_secondsolve <- 0 # def = 0
diff --git a/core/calculations.gms b/core/calculations.gms
index 9063d06f87..bf7e4bf3ef 100644
--- a/core/calculations.gms
+++ b/core/calculations.gms
@@ -21,6 +21,7 @@ $batinclude "./modules/include.gms" preloop
 * to be done here because a file declaration cannot be inside a loop
 file dummy; dummy.pw=2000; put dummy;
 
+File optfile /conopt4.opt/;
 
 ************************OPTIMIZATION PROCESS START******************************
 * This section contains only sourcecode that is directly connected to the
diff --git a/modules/18_residues/disaggRes_apr25/.equations.gms.swp b/modules/18_residues/disaggRes_apr25/.equations.gms.swp
new file mode 100644
index 0000000000..194e85b3e3
Binary files /dev/null and b/modules/18_residues/disaggRes_apr25/.equations.gms.swp differ
diff --git a/modules/18_residues/disaggRes_apr25/declarations.gms b/modules/18_residues/disaggRes_apr25/declarations.gms
new file mode 100644
index 0000000000..c1a7d51b00
--- /dev/null
+++ b/modules/18_residues/disaggRes_apr25/declarations.gms
@@ -0,0 +1,75 @@
+*** |  (C) 2008-2025 Potsdam Institute for Climate Impact Research (PIK)
+*** |  authors, and contributors see CITATION.cff file. This file is part
+*** |  of MAgPIE and licensed under AGPL-3.0-or-later. Under Section 7 of
+*** |  AGPL-3.0, you are granted additional permissions described in the
+*** |  MAgPIE License Exception, version 1.0 (see LICENSE file).
+*** |  Contact: magpie@pik-potsdam.de
+
+
+positive variables
+ v18_prod_res(j,kres)                       Cellular production of residues (mio. tDM)
+ vm_res_biomass_ag(i,kcr,w,dm_cnr)      Production of aboveground residues in each region (mio. tDM)
+ vm_res_biomass_bg(i,kcr,w,dm_cnr)          Production of belowground residues in each region (mio. tDM)
+ vm_res_ag_burn(i,kcr,w,dm_cnr)         Residues burned on fields in respective attribute units DM GJ Nr P K WM C (mio. tX)
+ vm_res_recycling(i,kcr,w,dm_cnr)       Residues recycled to croplands in respective nutrients Nr P K units (mio. tX)
+ vm_cost_prod_kres(i,kres)                  Production costs of harvesting crop residues (mio. USD17MER per yr)
+ v18_res_ag_removal_clust(j,kcr,w,dm_cnr)   Removal of crop residues in respective attribute units DM GJ Nr P K WM C (mio. tX)
+ v18_res_ag_recycling_clust(j,kcr,w,dm_cnr) Recylcing of crop residues to soils in respective attribute units DM GJ Nr P K WM C (mio. tX)
+;
+
+variables
+ v18_res_biomass_ag_clust(j,kcr,w,dm_cnr)   Production of aboveground residues in each cluster (mio. tDM)
+ v18_res_biomass_bg_clust(j,kcr,w,dm_cnr)   Production of belowground residues in each cluster (mio. tDM)
+ v18_res_ag_burn_clust(j,kcr,w,dm_cnr)      Residues burned on fields in respective attribute units DM GJ Nr P K WM C in each cluster (mio. tX)
+ v18_res_recycling_clust(j,kcr,w,dm_cnr)    Residues recycled to croplands in respective nutrients Nr P K units in each cluster (mio. tX)
+;
+
+equations
+ q18_prod_res_ag_clust(j,kcr,w,dm_cnr)        Production constraint of aboveground residues (mio. tDM)
+ q18_sumreg_res_biomass_ag(i,kcr,w,dm_cnr)    Regional above-ground residue biomass (mio. tX per yr)
+ q18_prod_res_bg_clust(j,kcr,w,dm_cnr)            Production constraint of belowground residues (mio. tDM)
+ q18_sumreg_res_biomass_bg(i,kcr,w,dm_cnr)        Regional below-ground residue biomass (mio. tX per yr)
+ q18_res_field_balance_clust(j,kcr,w,dm_cnr)  Calculation of the residues amount recycled to soils (mio. tDM)
+ q18_res_field_burn_clust(j,kcr,w,dm_cnr)     Fixing of the residues amount burned in a cluster in respective attribute units DM GJ Nr P K WM C (mio. tX)
+ q18_sumreg_res_biomass_burn(i,kcr,w,dm_cnr)  Regional burned residue biomass (mio. tX per yr)
+ q18_translate(j,kres,dm_cnr)           Transformation of the multiple crop residues into supply balance crop redisues in respective attribute units DM GJ Nr P K WM C (mio. tX) 
+ q18_prod_res_cell(i,kres)                  Allows for distribution of residues to cellular level (mio. tDM)
+ q18_res_recycling_cnr_clust(j,kcr,w,cnr)        Nutrient recycling of carbon and reaactive nitrogen (mio. tX)
+ q18_sumreg_res_recycling(i,kcr,w,cnr)     Regional recycled residue biomass (mio. tX per yr)
+ q18_cost_prod_res(i,kres)                  Production costs of harvesting crop residues (mio. USD17MER)
+;
+
+parameters
+ i18_res_use_burn(t_all,dev18,kcr)          Share of residues burned on field (1)
+;
+
+*#################### R SECTION START (OUTPUT DECLARATIONS) ####################
+parameters
+ ov18_prod_res(t,j,kres,type)                        Cellular production of residues (mio. tDM)
+ ov_res_biomass_ag(t,i,kcr,w,dm_cnr,type)            Production of aboveground residues in each region (mio. tDM)
+ ov_res_biomass_bg(t,i,kcr,w,dm_cnr,type)            Production of belowground residues in each region (mio. tDM)
+ ov_res_ag_burn(t,i,kcr,w,dm_cnr,type)               Residues burned on fields in respective attribute units DM GJ Nr P K WM C (mio. tX)
+ ov_res_recycling(t,i,kcr,w,dm_cnr,type)             Residues recycled to croplands in respective nutrients Nr P K units (mio. tX)
+ ov_cost_prod_kres(t,i,kres,type)                    Production costs of harvesting crop residues (mio. USD17MER per yr)
+ ov18_res_ag_removal_clust(t,j,kcr,w,dm_cnr,type)    Removal of crop residues in respective attribute units DM GJ Nr P K WM C (mio. tX)
+ ov18_res_ag_recycling_clust(t,j,kcr,w,dm_cnr,type)  Recylcing of crop residues to soils in respective attribute units DM GJ Nr P K WM C (mio. tX)
+ ov18_res_biomass_ag_clust(t,j,kcr,w,dm_cnr,type)    Production of aboveground residues in each cluster (mio. tDM)
+ ov18_res_biomass_bg_clust(t,j,kcr,w,dm_cnr,type)    Production of belowground residues in each cluster (mio. tDM)
+ ov18_res_ag_burn_clust(t,j,kcr,w,dm_cnr,type)       Residues burned on fields in respective attribute units DM GJ Nr P K WM C in each cluster (mio. tX)
+ ov18_res_recycling_clust(t,j,kcr,w,dm_cnr,type)     Residues recycled to croplands in respective nutrients Nr P K units in each cluster (mio. tX)
+ oq18_prod_res_ag_clust(t,j,kcr,w,dm_cnr,type)       Production constraint of aboveground residues (mio. tDM)
+ oq18_sumreg_res_biomass_ag(t,i,kcr,w,dm_cnr,type)   Regional above-ground residue biomass (mio. tX per yr)
+ oq18_prod_res_bg_clust(t,j,kcr,w,dm_cnr,type)       Production constraint of belowground residues (mio. tDM)
+ oq18_sumreg_res_biomass_bg(t,i,kcr,w,dm_cnr,type)   Regional below-ground residue biomass (mio. tX per yr)
+ oq18_res_field_balance_clust(t,j,kcr,w,dm_cnr,type) Calculation of the residues amount recycled to soils (mio. tDM)
+ oq18_res_field_burn_clust(t,j,kcr,w,dm_cnr,type)    Fixing of the residues amount burned in a cluster in respective attribute units DM GJ Nr P K WM C (mio. tX)
+ oq18_sumreg_res_biomass_burn(t,i,kcr,w,dm_cnr,type) Regional burned residue biomass (mio. tX per yr)
+ oq18_translate(t,j,kres,dm_cnr,type)                Transformation of the multiple crop residues into supply balance crop redisues in respective attribute units DM GJ Nr P K WM C (mio. tX)
+ oq18_prod_res_cell(t,i,kres,type)                   Allows for distribution of residues to cellular level (mio. tDM)
+ oq18_res_recycling_cnr_clust(t,j,kcr,w,cnr,type)    Nutrient recycling of carbon and reaactive nitrogen (mio. tX)
+ oq18_sumreg_res_recycling(t,i,kcr,w,cnr,type)       Regional recycled residue biomass (mio. tX per yr)
+ oq18_cost_prod_res(t,i,kres,type)                   Production costs of harvesting crop residues (mio. USD17MER)
+;
+*##################### R SECTION END (OUTPUT DECLARATIONS) #####################
+
+*** EOF declarations.gms ***
diff --git a/modules/18_residues/disaggRes_apr25/equations.gms b/modules/18_residues/disaggRes_apr25/equations.gms
new file mode 100644
index 0000000000..374c4f3700
--- /dev/null
+++ b/modules/18_residues/disaggRes_apr25/equations.gms
@@ -0,0 +1,126 @@
+*** |  (C) 2008-2025 Potsdam Institute for Climate Impact Research (PIK)
+*** |  authors, and contributors see CITATION.cff file. This file is part
+*** |  of MAgPIE and licensed under AGPL-3.0-or-later. Under Section 7 of
+*** |  AGPL-3.0, you are granted additional permissions described in the
+*** |  MAgPIE License Exception, version 1.0 (see LICENSE file).
+*** |  Contact: magpie@pik-potsdam.de
+
+*' @equations
+
+*' The AG crop residue biomass `vm_res_biomass_ag` is calculated as a function
+*' of harvested area `vm_area` and production `vm_prod_reg`. `f18_cgf` contains
+*' slope and intercept parameters of the CGFs.
+
+ q18_sumreg_res_biomass_ag(i2,kcr,w,dm_cnr) ..
+                 vm_res_biomass_ag(i2,kcr,w,dm_cnr) =e=
+                 sum(cell(i2,j2), v18_res_biomass_ag_clust(j2,kcr,w,dm_cnr));
+
+
+ q18_prod_res_ag_clust(j2,kcr,w,dm_cnr) ..
+                 v18_res_biomass_ag_clust(j2,kcr,w,dm_cnr)
+                 =e=
+                 (vm_area(j2,kcr,w) * sum((ct, cell(i2,j2)), f18_multicropping(ct,i2)) * f18_cgf("intercept",kcr)
+                  + vm_prod_kcr_w(j2,kcr,w) * f18_cgf("slope",kcr))
+                 * f18_attributes_residue_ag(dm_cnr,kcr);
+
+*' The BG crop residue biomass `vm_res_biomass_bg` is calculated as a function of
+*' total aboveground biomass.
+
+
+ q18_prod_res_bg_clust(j2,kcr,w,dm_cnr) ..
+                 v18_res_biomass_bg_clust(j2,kcr,w,dm_cnr)
+                 =e=
+                 (vm_prod_kcr_w(j2,kcr,w) +
+                   v18_res_biomass_ag_clust(j2,kcr,w,"dm")) * f18_cgf("bg_to_ag",kcr)
+                 * f18_attributes_residue_bg(dm_cnr,kcr);
+
+ q18_sumreg_res_biomass_bg(i2,kcr,w,dm_cnr) ..
+                 vm_res_biomass_bg(i2,kcr,w,dm_cnr) =e=
+                 sum(cell(i2,j2), v18_res_biomass_bg_clust(j2,kcr,w,dm_cnr));
+
+*' In contrast to AG biomass, AG production `vm_res_biomass_ag(i,kcr,dm_cnr)`
+*' is defined as the part of residues which is removed from the field. The
+*' difference between biomass and production is either burned on field or
+*' remains on the fields (either incorporated in soils or not) and decays.
+*' The field balance equations ensures that the production of AG residues
+*' `vm_res_biomass_ag(i,kcr,dm_cnr)` is properly assigned to different uses:
+*' removal, on-field burning and recycling of AG residues.
+ 
+ q18_res_field_balance_clust(j2,kcr,w,dm_cnr) ..
+                  v18_res_biomass_ag_clust(j2,kcr,w,dm_cnr)
+                  =e=
+                  v18_res_ag_removal_clust(j2,kcr,w,dm_cnr)
+                  + v18_res_ag_burn_clust(j2,kcr,w,dm_cnr)
+                  + v18_res_ag_recycling_clust(j2,kcr,w,dm_cnr);
+
+*' The amount of residues burned on fields in a region `vm_res_ag_burn` is
+*' determined by the share (ic18_res_use_min_shr) of AG residue biomass.
+*' Based on @smil_nitrogen_1999, residue burning is fixed to 15% of total AG
+*' crop residue dry matter in developed and 25% in developing regions for each
+*' crop. For future time steps, these rates are scenario dependent, and either
+*' kept constant or reduced to 10% and 0% in 2050.
+
+ q18_res_field_burn_clust(j2,kcr,w,dm_cnr) ..
+                  v18_res_ag_burn_clust(j2,kcr,w,dm_cnr)
+                  =e=
+                  sum((cell(i2,j2),ct), im_development_state(ct,i2) * i18_res_use_burn(ct,"high_income",kcr)
+                  + (1-im_development_state(ct,i2)) * i18_res_use_burn(ct,"low_income",kcr))
+                  * v18_res_biomass_ag_clust(j2,kcr,w,dm_cnr);
+
+ q18_sumreg_res_biomass_burn(i2,kcr,w,dm_cnr) ..
+                 vm_res_ag_burn(i2,kcr,w,dm_cnr) =e=
+                 sum(cell(i2,j2), v18_res_ag_burn_clust(j2,kcr,w,dm_cnr));
+
+*' While the residue biomass is estiamted with a crop-specific nutrient
+*' composition (which is required for consistent nutrient budgets), the
+*' removed residues are assumed to have homogeneous properties
+*' (to reduce the number of commodities in MAgPIE) within three crop residue
+*' groups (cereal straw, fibrous residues that cannot be digested
+*' by monogastrics, and non-fibrous residues that can be digested).
+*' The following constraint, in combination with the field balance equation,
+*' guarantees that mass balances are not violated while a homogeneous
+*' good is extracted from heterogeneous goods.
+
+ q18_translate(j2,kres,dm_cnr)..
+                  sum((kres_kcr(kres,kcr),w), v18_res_ag_removal_clust(j2,kcr,w,dm_cnr))
+                  =e=
+                  v18_prod_res(j2,kres) * fm_attributes(dm_cnr,kres);
+
+*' sum to the regional amount of residues produced for the regional interface
+
+ q18_prod_res_cell(i2,kres)..
+                  sum(cell(i2,j2), v18_prod_res(j2,kres))
+                  =e=
+                  vm_prod_reg(i2,kres) ;
+
+*' Residues recycled to croplands in nutrients `vm_res_recycling(i2,"nr")` are
+*' calcualted based on the amount of AG residues left on field for recycling, the
+*' nutrients coming from burned residues, and on biomass that is left in
+*' BG residues. They are calculated to be transmitted to the nitrogen budget
+*' module [50_nr_soil_budget].
+
+ q18_res_recycling_cnr_clust(j2,kcr,w,cnr) ..
+                  v18_res_recycling_clust(j2,kcr,w,cnr)
+                  =e=
+                  v18_res_ag_recycling_clust(j2,kcr,w,cnr)
+                    + v18_res_ag_burn_clust(j2,kcr,w,cnr)*(1-f18_res_combust_eff(kcr))
+                    + v18_res_biomass_bg_clust(j2,kcr,w,cnr)
+                  ;
+
+ q18_sumreg_res_recycling(i2,kcr,w,cnr) ..
+                 vm_res_recycling(i2,kcr,w,cnr) =e=
+                 sum(cell(i2,j2), v18_res_recycling_clust(j2,kcr,w,cnr));
+
+*' Costs of residue harvest are based on straw baling and hauling from 
+*' Budynski, Stephanie. 2020. Straw Manufacturing in Alberta (@budynski_straw_2020), 
+*' using the lower range of the US costs.
+
+ q18_cost_prod_res(i2,kres) ..
+                  vm_cost_prod_kres(i2,kres)
+                  =e=
+                  vm_prod_reg(i2,kres) * fm_attributes("wm",kres)  *  f18_fac_req_kres(kres);
+
+*' Trade of AG residues is not considered, so that all produced AG residues have
+*' to be assigned to uses within the respective world region.
+
+*** EOF constraints.gms ***
diff --git a/modules/18_residues/flexcluster_jul23/input.gms b/modules/18_residues/disaggRes_apr25/input.gms
similarity index 81%
rename from modules/18_residues/flexcluster_jul23/input.gms
rename to modules/18_residues/disaggRes_apr25/input.gms
index 0e2ed9f46e..b098d0fc8c 100644
--- a/modules/18_residues/flexcluster_jul23/input.gms
+++ b/modules/18_residues/disaggRes_apr25/input.gms
@@ -19,19 +19,19 @@ $include "./modules/18_residues/input/f18_attributes_residue_ag.csv"
 $offdelim;
 
 
-table f18_attributes_residue_bg(dm_nr,kve) Nutrient content of belowground crop residues in reactive nitorgen and carbon units Nr C (X per DM)
+table f18_attributes_residue_bg(dm_cnr,kve) Nutrient content of belowground crop residues in reactive nitorgen and carbon units Nr C (X per DM)
 $ondelim
 $include "./modules/18_residues/input/f18_attributes_residue_bg.csv"
 $offdelim;
 
 table f18_cgf(cgf,kve) Crop growth functions for all vegetation types containing slope intercept and belowground to aboveground ratio (1)
 $ondelim
-$include "./modules/18_residues/flexcluster_jul23/input/f18_cgf.csv"
+$include "./modules/18_residues/disaggRes_apr25/input/f18_cgf.csv"
 $offdelim;
 
 table f18_res_use_burn(t_all,burn_scen18,dev18,kcr) Minimum and maximum burn share use for residues developing over time (1)
 $ondelim
-$include "./modules/18_residues/flexcluster_jul23/input/f18_res_use_burn.cs3"
+$include "./modules/18_residues/disaggRes_apr25/input/f18_res_use_burn.cs3"
 $offdelim;
 
 parameter f18_res_combust_eff(kve)  Combustion efficiency of residue burning (1)
@@ -44,7 +44,7 @@ $offdelim
 parameter f18_fac_req_kres(kres) Factor requirements (USD17MER per tDM)
 /
 $ondelim
-$include "./modules/18_residues/flexcluster_jul23/input/f18_fac_req_kres.csv"
+$include "./modules/18_residues/disaggRes_apr25/input/f18_fac_req_kres.csv"
 $offdelim
 /;
 
diff --git a/modules/18_residues/flexcluster_jul23/input/files b/modules/18_residues/disaggRes_apr25/input/files
similarity index 100%
rename from modules/18_residues/flexcluster_jul23/input/files
rename to modules/18_residues/disaggRes_apr25/input/files
diff --git a/modules/18_residues/disaggRes_apr25/postsolve.gms b/modules/18_residues/disaggRes_apr25/postsolve.gms
new file mode 100644
index 0000000000..cac2de2964
--- /dev/null
+++ b/modules/18_residues/disaggRes_apr25/postsolve.gms
@@ -0,0 +1,110 @@
+*** |  (C) 2008-2025 Potsdam Institute for Climate Impact Research (PIK)
+*** |  authors, and contributors see CITATION.cff file. This file is part
+*** |  of MAgPIE and licensed under AGPL-3.0-or-later. Under Section 7 of
+*** |  AGPL-3.0, you are granted additional permissions described in the
+*** |  MAgPIE License Exception, version 1.0 (see LICENSE file).
+*** |  Contact: magpie@pik-potsdam.de
+
+****** Residues
+
+*** EOF postsolve.gms ***
+
+*#################### R SECTION START (OUTPUT DEFINITIONS) #####################
+ ov18_prod_res(t,j,kres,"marginal")                        = v18_prod_res.m(j,kres);
+ ov_res_biomass_ag(t,i,kcr,w,dm_cnr,"marginal")            = vm_res_biomass_ag.m(i,kcr,w,dm_cnr);
+ ov_res_biomass_bg(t,i,kcr,w,dm_cnr,"marginal")            = vm_res_biomass_bg.m(i,kcr,w,dm_cnr);
+ ov_res_ag_burn(t,i,kcr,w,dm_cnr,"marginal")               = vm_res_ag_burn.m(i,kcr,w,dm_cnr);
+ ov_res_recycling(t,i,kcr,w,dm_cnr,"marginal")             = vm_res_recycling.m(i,kcr,w,dm_cnr);
+ ov_cost_prod_kres(t,i,kres,"marginal")                    = vm_cost_prod_kres.m(i,kres);
+ ov18_res_ag_removal_clust(t,j,kcr,w,dm_cnr,"marginal")    = v18_res_ag_removal_clust.m(j,kcr,w,dm_cnr);
+ ov18_res_ag_recycling_clust(t,j,kcr,w,dm_cnr,"marginal")  = v18_res_ag_recycling_clust.m(j,kcr,w,dm_cnr);
+ ov18_res_biomass_ag_clust(t,j,kcr,w,dm_cnr,"marginal")    = v18_res_biomass_ag_clust.m(j,kcr,w,dm_cnr);
+ ov18_res_biomass_bg_clust(t,j,kcr,w,dm_cnr,"marginal")    = v18_res_biomass_bg_clust.m(j,kcr,w,dm_cnr);
+ ov18_res_ag_burn_clust(t,j,kcr,w,dm_cnr,"marginal")       = v18_res_ag_burn_clust.m(j,kcr,w,dm_cnr);
+ ov18_res_recycling_clust(t,j,kcr,w,dm_cnr,"marginal")     = v18_res_recycling_clust.m(j,kcr,w,dm_cnr);
+ oq18_prod_res_ag_clust(t,j,kcr,w,dm_cnr,"marginal")       = q18_prod_res_ag_clust.m(j,kcr,w,dm_cnr);
+ oq18_sumreg_res_biomass_ag(t,i,kcr,w,dm_cnr,"marginal")   = q18_sumreg_res_biomass_ag.m(i,kcr,w,dm_cnr);
+ oq18_prod_res_bg_clust(t,j,kcr,w,dm_cnr,"marginal")       = q18_prod_res_bg_clust.m(j,kcr,w,dm_cnr);
+ oq18_sumreg_res_biomass_bg(t,i,kcr,w,dm_cnr,"marginal")   = q18_sumreg_res_biomass_bg.m(i,kcr,w,dm_cnr);
+ oq18_res_field_balance_clust(t,j,kcr,w,dm_cnr,"marginal") = q18_res_field_balance_clust.m(j,kcr,w,dm_cnr);
+ oq18_res_field_burn_clust(t,j,kcr,w,dm_cnr,"marginal")    = q18_res_field_burn_clust.m(j,kcr,w,dm_cnr);
+ oq18_sumreg_res_biomass_burn(t,i,kcr,w,dm_cnr,"marginal") = q18_sumreg_res_biomass_burn.m(i,kcr,w,dm_cnr);
+ oq18_translate(t,j,kres,dm_cnr,"marginal")                = q18_translate.m(j,kres,dm_cnr);
+ oq18_prod_res_cell(t,i,kres,"marginal")                   = q18_prod_res_cell.m(i,kres);
+ oq18_res_recycling_cnr_clust(t,j,kcr,w,cnr,"marginal")    = q18_res_recycling_cnr_clust.m(j,kcr,w,cnr);
+ oq18_sumreg_res_recycling(t,i,kcr,w,cnr,"marginal")       = q18_sumreg_res_recycling.m(i,kcr,w,cnr);
+ oq18_cost_prod_res(t,i,kres,"marginal")                   = q18_cost_prod_res.m(i,kres);
+ ov18_prod_res(t,j,kres,"level")                           = v18_prod_res.l(j,kres);
+ ov_res_biomass_ag(t,i,kcr,w,dm_cnr,"level")               = vm_res_biomass_ag.l(i,kcr,w,dm_cnr);
+ ov_res_biomass_bg(t,i,kcr,w,dm_cnr,"level")               = vm_res_biomass_bg.l(i,kcr,w,dm_cnr);
+ ov_res_ag_burn(t,i,kcr,w,dm_cnr,"level")                  = vm_res_ag_burn.l(i,kcr,w,dm_cnr);
+ ov_res_recycling(t,i,kcr,w,dm_cnr,"level")                = vm_res_recycling.l(i,kcr,w,dm_cnr);
+ ov_cost_prod_kres(t,i,kres,"level")                       = vm_cost_prod_kres.l(i,kres);
+ ov18_res_ag_removal_clust(t,j,kcr,w,dm_cnr,"level")       = v18_res_ag_removal_clust.l(j,kcr,w,dm_cnr);
+ ov18_res_ag_recycling_clust(t,j,kcr,w,dm_cnr,"level")     = v18_res_ag_recycling_clust.l(j,kcr,w,dm_cnr);
+ ov18_res_biomass_ag_clust(t,j,kcr,w,dm_cnr,"level")       = v18_res_biomass_ag_clust.l(j,kcr,w,dm_cnr);
+ ov18_res_biomass_bg_clust(t,j,kcr,w,dm_cnr,"level")       = v18_res_biomass_bg_clust.l(j,kcr,w,dm_cnr);
+ ov18_res_ag_burn_clust(t,j,kcr,w,dm_cnr,"level")          = v18_res_ag_burn_clust.l(j,kcr,w,dm_cnr);
+ ov18_res_recycling_clust(t,j,kcr,w,dm_cnr,"level")        = v18_res_recycling_clust.l(j,kcr,w,dm_cnr);
+ oq18_prod_res_ag_clust(t,j,kcr,w,dm_cnr,"level")          = q18_prod_res_ag_clust.l(j,kcr,w,dm_cnr);
+ oq18_sumreg_res_biomass_ag(t,i,kcr,w,dm_cnr,"level")      = q18_sumreg_res_biomass_ag.l(i,kcr,w,dm_cnr);
+ oq18_prod_res_bg_clust(t,j,kcr,w,dm_cnr,"level")          = q18_prod_res_bg_clust.l(j,kcr,w,dm_cnr);
+ oq18_sumreg_res_biomass_bg(t,i,kcr,w,dm_cnr,"level")      = q18_sumreg_res_biomass_bg.l(i,kcr,w,dm_cnr);
+ oq18_res_field_balance_clust(t,j,kcr,w,dm_cnr,"level")    = q18_res_field_balance_clust.l(j,kcr,w,dm_cnr);
+ oq18_res_field_burn_clust(t,j,kcr,w,dm_cnr,"level")       = q18_res_field_burn_clust.l(j,kcr,w,dm_cnr);
+ oq18_sumreg_res_biomass_burn(t,i,kcr,w,dm_cnr,"level")    = q18_sumreg_res_biomass_burn.l(i,kcr,w,dm_cnr);
+ oq18_translate(t,j,kres,dm_cnr,"level")                   = q18_translate.l(j,kres,dm_cnr);
+ oq18_prod_res_cell(t,i,kres,"level")                      = q18_prod_res_cell.l(i,kres);
+ oq18_res_recycling_cnr_clust(t,j,kcr,w,cnr,"level")       = q18_res_recycling_cnr_clust.l(j,kcr,w,cnr);
+ oq18_sumreg_res_recycling(t,i,kcr,w,cnr,"level")          = q18_sumreg_res_recycling.l(i,kcr,w,cnr);
+ oq18_cost_prod_res(t,i,kres,"level")                      = q18_cost_prod_res.l(i,kres);
+ ov18_prod_res(t,j,kres,"upper")                           = v18_prod_res.up(j,kres);
+ ov_res_biomass_ag(t,i,kcr,w,dm_cnr,"upper")               = vm_res_biomass_ag.up(i,kcr,w,dm_cnr);
+ ov_res_biomass_bg(t,i,kcr,w,dm_cnr,"upper")               = vm_res_biomass_bg.up(i,kcr,w,dm_cnr);
+ ov_res_ag_burn(t,i,kcr,w,dm_cnr,"upper")                  = vm_res_ag_burn.up(i,kcr,w,dm_cnr);
+ ov_res_recycling(t,i,kcr,w,dm_cnr,"upper")                = vm_res_recycling.up(i,kcr,w,dm_cnr);
+ ov_cost_prod_kres(t,i,kres,"upper")                       = vm_cost_prod_kres.up(i,kres);
+ ov18_res_ag_removal_clust(t,j,kcr,w,dm_cnr,"upper")       = v18_res_ag_removal_clust.up(j,kcr,w,dm_cnr);
+ ov18_res_ag_recycling_clust(t,j,kcr,w,dm_cnr,"upper")     = v18_res_ag_recycling_clust.up(j,kcr,w,dm_cnr);
+ ov18_res_biomass_ag_clust(t,j,kcr,w,dm_cnr,"upper")       = v18_res_biomass_ag_clust.up(j,kcr,w,dm_cnr);
+ ov18_res_biomass_bg_clust(t,j,kcr,w,dm_cnr,"upper")       = v18_res_biomass_bg_clust.up(j,kcr,w,dm_cnr);
+ ov18_res_ag_burn_clust(t,j,kcr,w,dm_cnr,"upper")          = v18_res_ag_burn_clust.up(j,kcr,w,dm_cnr);
+ ov18_res_recycling_clust(t,j,kcr,w,dm_cnr,"upper")        = v18_res_recycling_clust.up(j,kcr,w,dm_cnr);
+ oq18_prod_res_ag_clust(t,j,kcr,w,dm_cnr,"upper")          = q18_prod_res_ag_clust.up(j,kcr,w,dm_cnr);
+ oq18_sumreg_res_biomass_ag(t,i,kcr,w,dm_cnr,"upper")      = q18_sumreg_res_biomass_ag.up(i,kcr,w,dm_cnr);
+ oq18_prod_res_bg_clust(t,j,kcr,w,dm_cnr,"upper")          = q18_prod_res_bg_clust.up(j,kcr,w,dm_cnr);
+ oq18_sumreg_res_biomass_bg(t,i,kcr,w,dm_cnr,"upper")      = q18_sumreg_res_biomass_bg.up(i,kcr,w,dm_cnr);
+ oq18_res_field_balance_clust(t,j,kcr,w,dm_cnr,"upper")    = q18_res_field_balance_clust.up(j,kcr,w,dm_cnr);
+ oq18_res_field_burn_clust(t,j,kcr,w,dm_cnr,"upper")       = q18_res_field_burn_clust.up(j,kcr,w,dm_cnr);
+ oq18_sumreg_res_biomass_burn(t,i,kcr,w,dm_cnr,"upper")    = q18_sumreg_res_biomass_burn.up(i,kcr,w,dm_cnr);
+ oq18_translate(t,j,kres,dm_cnr,"upper")                   = q18_translate.up(j,kres,dm_cnr);
+ oq18_prod_res_cell(t,i,kres,"upper")                      = q18_prod_res_cell.up(i,kres);
+ oq18_res_recycling_cnr_clust(t,j,kcr,w,cnr,"upper")       = q18_res_recycling_cnr_clust.up(j,kcr,w,cnr);
+ oq18_sumreg_res_recycling(t,i,kcr,w,cnr,"upper")          = q18_sumreg_res_recycling.up(i,kcr,w,cnr);
+ oq18_cost_prod_res(t,i,kres,"upper")                      = q18_cost_prod_res.up(i,kres);
+ ov18_prod_res(t,j,kres,"lower")                           = v18_prod_res.lo(j,kres);
+ ov_res_biomass_ag(t,i,kcr,w,dm_cnr,"lower")               = vm_res_biomass_ag.lo(i,kcr,w,dm_cnr);
+ ov_res_biomass_bg(t,i,kcr,w,dm_cnr,"lower")               = vm_res_biomass_bg.lo(i,kcr,w,dm_cnr);
+ ov_res_ag_burn(t,i,kcr,w,dm_cnr,"lower")                  = vm_res_ag_burn.lo(i,kcr,w,dm_cnr);
+ ov_res_recycling(t,i,kcr,w,dm_cnr,"lower")                = vm_res_recycling.lo(i,kcr,w,dm_cnr);
+ ov_cost_prod_kres(t,i,kres,"lower")                       = vm_cost_prod_kres.lo(i,kres);
+ ov18_res_ag_removal_clust(t,j,kcr,w,dm_cnr,"lower")       = v18_res_ag_removal_clust.lo(j,kcr,w,dm_cnr);
+ ov18_res_ag_recycling_clust(t,j,kcr,w,dm_cnr,"lower")     = v18_res_ag_recycling_clust.lo(j,kcr,w,dm_cnr);
+ ov18_res_biomass_ag_clust(t,j,kcr,w,dm_cnr,"lower")       = v18_res_biomass_ag_clust.lo(j,kcr,w,dm_cnr);
+ ov18_res_biomass_bg_clust(t,j,kcr,w,dm_cnr,"lower")       = v18_res_biomass_bg_clust.lo(j,kcr,w,dm_cnr);
+ ov18_res_ag_burn_clust(t,j,kcr,w,dm_cnr,"lower")          = v18_res_ag_burn_clust.lo(j,kcr,w,dm_cnr);
+ ov18_res_recycling_clust(t,j,kcr,w,dm_cnr,"lower")        = v18_res_recycling_clust.lo(j,kcr,w,dm_cnr);
+ oq18_prod_res_ag_clust(t,j,kcr,w,dm_cnr,"lower")          = q18_prod_res_ag_clust.lo(j,kcr,w,dm_cnr);
+ oq18_sumreg_res_biomass_ag(t,i,kcr,w,dm_cnr,"lower")      = q18_sumreg_res_biomass_ag.lo(i,kcr,w,dm_cnr);
+ oq18_prod_res_bg_clust(t,j,kcr,w,dm_cnr,"lower")          = q18_prod_res_bg_clust.lo(j,kcr,w,dm_cnr);
+ oq18_sumreg_res_biomass_bg(t,i,kcr,w,dm_cnr,"lower")      = q18_sumreg_res_biomass_bg.lo(i,kcr,w,dm_cnr);
+ oq18_res_field_balance_clust(t,j,kcr,w,dm_cnr,"lower")    = q18_res_field_balance_clust.lo(j,kcr,w,dm_cnr);
+ oq18_res_field_burn_clust(t,j,kcr,w,dm_cnr,"lower")       = q18_res_field_burn_clust.lo(j,kcr,w,dm_cnr);
+ oq18_sumreg_res_biomass_burn(t,i,kcr,w,dm_cnr,"lower")    = q18_sumreg_res_biomass_burn.lo(i,kcr,w,dm_cnr);
+ oq18_translate(t,j,kres,dm_cnr,"lower")                   = q18_translate.lo(j,kres,dm_cnr);
+ oq18_prod_res_cell(t,i,kres,"lower")                      = q18_prod_res_cell.lo(i,kres);
+ oq18_res_recycling_cnr_clust(t,j,kcr,w,cnr,"lower")       = q18_res_recycling_cnr_clust.lo(j,kcr,w,cnr);
+ oq18_sumreg_res_recycling(t,i,kcr,w,cnr,"lower")          = q18_sumreg_res_recycling.lo(i,kcr,w,cnr);
+ oq18_cost_prod_res(t,i,kres,"lower")                      = q18_cost_prod_res.lo(i,kres);
+*##################### R SECTION END (OUTPUT DEFINITIONS) ######################
+
diff --git a/modules/18_residues/flexcluster_jul23/preloop.gms b/modules/18_residues/disaggRes_apr25/preloop.gms
similarity index 100%
rename from modules/18_residues/flexcluster_jul23/preloop.gms
rename to modules/18_residues/disaggRes_apr25/preloop.gms
diff --git a/modules/18_residues/flexcluster_jul23/presolve.gms b/modules/18_residues/disaggRes_apr25/presolve.gms
similarity index 88%
rename from modules/18_residues/flexcluster_jul23/presolve.gms
rename to modules/18_residues/disaggRes_apr25/presolve.gms
index be2459d824..7e152307fa 100644
--- a/modules/18_residues/flexcluster_jul23/presolve.gms
+++ b/modules/18_residues/disaggRes_apr25/presolve.gms
@@ -5,6 +5,6 @@
 *** |  MAgPIE License Exception, version 1.0 (see LICENSE file).
 *** |  Contact: magpie@pik-potsdam.de
 
-v18_res_ag_removal.fx(j,nonused18,attributes)=0;
+v18_res_ag_removal_clust.fx(j,nonused18,w,dm_cnr)=0;
 
 *** EOF solve.gms ***
diff --git a/modules/18_residues/flexcluster_jul23/realization.gms b/modules/18_residues/disaggRes_apr25/realization.gms
similarity index 67%
rename from modules/18_residues/flexcluster_jul23/realization.gms
rename to modules/18_residues/disaggRes_apr25/realization.gms
index 084b9ac6b9..f0b95d5ba1 100644
--- a/modules/18_residues/flexcluster_jul23/realization.gms
+++ b/modules/18_residues/disaggRes_apr25/realization.gms
@@ -24,19 +24,14 @@
 *' on @wirsenius_human_2000, @lal_world_2005 and @feller_dungung_2007. If different CGFs are available
 *' for crops within a crop group, we build a weighted average based on the
 *' production in 1995.
-*' 
-*' This realization enforces cluster-level agricultural residue production, based on agricultural production
-*' at the same level. However, other uses such as burning and recycling are allowed to be balanced at the 
-*' regional level, in order to reduce computational complexity.
-
 
 *####################### R SECTION START (PHASES) ##############################
-$Ifi "%phase%" == "sets" $include "./modules/18_residues/flexcluster_jul23/sets.gms"
-$Ifi "%phase%" == "declarations" $include "./modules/18_residues/flexcluster_jul23/declarations.gms"
-$Ifi "%phase%" == "input" $include "./modules/18_residues/flexcluster_jul23/input.gms"
-$Ifi "%phase%" == "equations" $include "./modules/18_residues/flexcluster_jul23/equations.gms"
-$Ifi "%phase%" == "scaling" $include "./modules/18_residues/flexcluster_jul23/scaling.gms"
-$Ifi "%phase%" == "preloop" $include "./modules/18_residues/flexcluster_jul23/preloop.gms"
-$Ifi "%phase%" == "presolve" $include "./modules/18_residues/flexcluster_jul23/presolve.gms"
-$Ifi "%phase%" == "postsolve" $include "./modules/18_residues/flexcluster_jul23/postsolve.gms"
+$Ifi "%phase%" == "sets" $include "./modules/18_residues/disaggRes_apr25/sets.gms"
+$Ifi "%phase%" == "declarations" $include "./modules/18_residues/disaggRes_apr25/declarations.gms"
+$Ifi "%phase%" == "input" $include "./modules/18_residues/disaggRes_apr25/input.gms"
+$Ifi "%phase%" == "equations" $include "./modules/18_residues/disaggRes_apr25/equations.gms"
+$Ifi "%phase%" == "scaling" $include "./modules/18_residues/disaggRes_apr25/scaling.gms"
+$Ifi "%phase%" == "preloop" $include "./modules/18_residues/disaggRes_apr25/preloop.gms"
+$Ifi "%phase%" == "presolve" $include "./modules/18_residues/disaggRes_apr25/presolve.gms"
+$Ifi "%phase%" == "postsolve" $include "./modules/18_residues/disaggRes_apr25/postsolve.gms"
 *######################## R SECTION END (PHASES) ###############################
diff --git a/modules/18_residues/flexcluster_jul23/scaling.gms b/modules/18_residues/disaggRes_apr25/scaling.gms
similarity index 100%
rename from modules/18_residues/flexcluster_jul23/scaling.gms
rename to modules/18_residues/disaggRes_apr25/scaling.gms
diff --git a/modules/18_residues/flexcluster_jul23/sets.gms b/modules/18_residues/disaggRes_apr25/sets.gms
similarity index 88%
rename from modules/18_residues/flexcluster_jul23/sets.gms
rename to modules/18_residues/disaggRes_apr25/sets.gms
index 0ce45cea6c..74b6032e54 100644
--- a/modules/18_residues/flexcluster_jul23/sets.gms
+++ b/modules/18_residues/disaggRes_apr25/sets.gms
@@ -8,13 +8,13 @@
 
 sets
 
-dm_nr(attributes) dry matter and nr
+dm_cnr(attributes) dry matter carbon and nr
 /dm, nr, c/
 
-pk18(npk) subset of npk containing P and K nutrients
-/p, k/
+cnr(dm_cnr) carbon and nr
+/nr, c/
 
-dev18 country development indicator
+dev18 country develoment indicator
 /high_income,low_income/
 
 burn_scen18 scenario for burning residues on field
diff --git a/modules/18_residues/flexcluster_jul23/declarations.gms b/modules/18_residues/flexcluster_jul23/declarations.gms
deleted file mode 100644
index ab53bb9b53..0000000000
--- a/modules/18_residues/flexcluster_jul23/declarations.gms
+++ /dev/null
@@ -1,76 +0,0 @@
-*** |  (C) 2008-2025 Potsdam Institute for Climate Impact Research (PIK)
-*** |  authors, and contributors see CITATION.cff file. This file is part
-*** |  of MAgPIE and licensed under AGPL-3.0-or-later. Under Section 7 of
-*** |  AGPL-3.0, you are granted additional permissions described in the
-*** |  MAgPIE License Exception, version 1.0 (see LICENSE file).
-*** |  Contact: magpie@pik-potsdam.de
-
-
-positive variables
- v18_prod_res(j,kres)                       Cluster-level production of residues (mio. tDM)
- v18_res_biomass_ag_clust(j,kcr)            Production of aboveground residues in each cluster (mio. tDM)
- vm_res_biomass_ag(i,kcr,attributes)        Production of aboveground residues in each region (mio. tDM)
- vm_res_biomass_bg(i,kcr,dm_nr)             Production of belowground residues in each region (mio. tDM)
-
- v18_res_ag_removal(j,kcr,attributes)       Removal of crop residues in respective attribute units DM GJ Nr P K WM C (mio. tX)
- v18_res_ag_removal_reg(i,kcr,attributes)   Regional removal of crop residues in respective attribute units DM GJ Nr P K WM C (mio. tX)
- v18_res_ag_recycling(i,kcr,attributes)     Recycling of crop residues to soils in respective attribute units DM GJ Nr P K WM C (mio. tX)
- vm_res_ag_burn(i,kcr,attributes)           Regional residues burned on fields in respective attribute units DM GJ Nr P K WM C (mio. tX)
-
- vm_res_recycling(i,npk)                    Residues recycled to croplands in respective nutrients Nr P K units (mio. tX)
- vm_cost_prod_kres(i,kres)                  Production costs of harvesting crop residues (mio. USD17MER per yr)
-;
-
-equations
-
- q18_prod_res_ag_clust(j,kcr)               Cluster-level production constraint of aboveground residues (mio. tDM)
- q18_prod_res_ag_reg(i,kcr,attributes)      Regional production constraint of aboveground residues (mio. tDM)
-
- q18_prod_res_bg_clust(i,kcr,dm_nr)         Cluster-level production constraint of belowground residues (mio. tDM)
-
- q18_regional_removals(i,kcr,attributes)    Calculation of regional level removals (mio. tX)
- q18_res_field_balance(i,kcr,attributes)    Calculation of the residues amount recycled to soils (mio. tDM)
- q18_clust_field_constraint(j,kres)         Make sure the amount removed in any cluster does not exceed the amount available (mio. tDM)
- q18_res_field_burn(i,kcr,attributes)       Fixing of the residues amount burned in a region in respective attribute units DM GJ Nr P K WM C (mio. tX)
- q18_translate(j,kres,attributes)           Transformation of the multiple crop residues into supply balance crop residues in respective attribute units DM GJ Nr P K WM C (mio. tX)
-
- q18_res_recycling_nr(i)                    Nutrient recycling of reaactive nitrogen (mio. tNr)
- q18_res_recycling_pk(i,pk18)               Nutrient recycling of phosphorus and potash (mio. tX)
- q18_cost_prod_res(i,kres)                  Production costs of harvesting crop residues (mio. USD17MER)
-
- q18_prod_res_reg(i,kall)                   Regional production of residues (mio. tDM)
-
-;
-
-parameters
- i18_res_use_burn(t_all,dev18,kcr)          Share of residues burned on field (1)
-;
-
-*#################### R SECTION START (OUTPUT DECLARATIONS) ####################
-parameters
- ov18_prod_res(t,j,kres,type)                     Cluster-level production of residues (mio. tDM)
- ov18_res_biomass_ag_clust(t,j,kcr,type)          Production of aboveground residues in each cluster (mio. tDM)
- ov_res_biomass_ag(t,i,kcr,attributes,type)       Production of aboveground residues in each region (mio. tDM)
- ov_res_biomass_bg(t,i,kcr,dm_nr,type)            Production of belowground residues in each region (mio. tDM)
- ov18_res_ag_removal(t,j,kcr,attributes,type)     Removal of crop residues in respective attribute units DM GJ Nr P K WM C (mio. tX)
- ov18_res_ag_removal_reg(t,i,kcr,attributes,type) Regional removal of crop residues in respective attribute units DM GJ Nr P K WM C (mio. tX)
- ov18_res_ag_recycling(t,i,kcr,attributes,type)   Recycling of crop residues to soils in respective attribute units DM GJ Nr P K WM C (mio. tX)
- ov_res_ag_burn(t,i,kcr,attributes,type)          Regional residues burned on fields in respective attribute units DM GJ Nr P K WM C (mio. tX)
- ov_res_recycling(t,i,npk,type)                   Residues recycled to croplands in respective nutrients Nr P K units (mio. tX)
- ov_cost_prod_kres(t,i,kres,type)                 Production costs of harvesting crop residues (mio. USD17MER per yr)
- oq18_prod_res_ag_clust(t,j,kcr,type)             Cluster-level production constraint of aboveground residues (mio. tDM)
- oq18_prod_res_ag_reg(t,i,kcr,attributes,type)    Regional production constraint of aboveground residues (mio. tDM)
- oq18_prod_res_bg_clust(t,i,kcr,dm_nr,type)       Cluster-level production constraint of belowground residues (mio. tDM)
- oq18_regional_removals(t,i,kcr,attributes,type)  Calculation of regional level removals (mio. tX)
- oq18_res_field_balance(t,i,kcr,attributes,type)  Calculation of the residues amount recycled to soils (mio. tDM)
- oq18_clust_field_constraint(t,j,kres,type)       Make sure the amount removed in any cluster does not exceed the amount available (mio. tDM)
- oq18_res_field_burn(t,i,kcr,attributes,type)     Fixing of the residues amount burned in a region in respective attribute units DM GJ Nr P K WM C (mio. tX)
- oq18_translate(t,j,kres,attributes,type)         Transformation of the multiple crop residues into supply balance crop residues in respective attribute units DM GJ Nr P K WM C (mio. tX)
- oq18_res_recycling_nr(t,i,type)                  Nutrient recycling of reaactive nitrogen (mio. tNr)
- oq18_res_recycling_pk(t,i,pk18,type)             Nutrient recycling of phosphorus and potash (mio. tX)
- oq18_cost_prod_res(t,i,kres,type)                Production costs of harvesting crop residues (mio. USD17MER)
- oq18_prod_res_reg(t,i,kall,type)                 Regional production of residues (mio. tDM)
-;
-*##################### R SECTION END (OUTPUT DECLARATIONS) #####################
-
-*** EOF declarations.gms ***
diff --git a/modules/18_residues/flexcluster_jul23/equations.gms b/modules/18_residues/flexcluster_jul23/equations.gms
deleted file mode 100644
index 1a99e73d49..0000000000
--- a/modules/18_residues/flexcluster_jul23/equations.gms
+++ /dev/null
@@ -1,145 +0,0 @@
-*** |  (C) 2008-2025 Potsdam Institute for Climate Impact Research (PIK)
-*** |  authors, and contributors see CITATION.cff file. This file is part
-*** |  of MAgPIE and licensed under AGPL-3.0-or-later. Under Section 7 of
-*** |  AGPL-3.0, you are granted additional permissions described in the
-*** |  MAgPIE License Exception, version 1.0 (see LICENSE file).
-*** |  Contact: magpie@pik-potsdam.de
-
-*' @equations
-
-*' The AG crop residue biomass `vm_res_biomass_ag` is calculated as a function
-*' of harvested area `vm_area` and production `vm_prod_reg`. `f18_cgf` contains
-*' slope and intercept parameters of the CGFs.
-
- q18_prod_res_ag_clust(j2,kcr) ..
-                 v18_res_biomass_ag_clust(j2,kcr)
-                 =e=
-                 (sum(w, vm_area(j2,kcr,w)) * sum((ct, cell(i2,j2)), f18_multicropping(ct,i2)) * f18_cgf("intercept",kcr)
-                 + vm_prod(j2,kcr) * f18_cgf("slope",kcr));
-
- q18_prod_res_ag_reg(i2,kcr,attributes) ..
-                  vm_res_biomass_ag(i2,kcr,attributes)
-                 =e=
-                 sum(cell(i2,j2), v18_res_biomass_ag_clust(j2,kcr)) 
-                 * f18_attributes_residue_ag(attributes,kcr);
-
-*' The BG crop residue biomass `vm_res_biomass_bg` is calculated as a function of
-*' total aboveground biomass.
-
- q18_prod_res_bg_clust(i2,kcr,dm_nr) ..
-                 vm_res_biomass_bg(i2,kcr,dm_nr)
-                 =e=
-                 (vm_prod_reg(i2,kcr) + vm_res_biomass_ag(i2,kcr,"dm")) * f18_cgf("bg_to_ag",kcr)
-                 * f18_attributes_residue_bg(dm_nr,kcr);
-
-*' Variable of removals at regional level needs to be greater than 
-*' the regionally-summed cluster-level variable. This is not an equal-to
-*' for run-time considerations, but should be noted if regional removals 
-*' vm_res_biomass_ag are to be incentivised.
-
- q18_regional_removals(i2,kcr,attributes) ..
-                sum(cell(i2,j2), v18_res_ag_removal(j2,kcr,attributes))
-                =e=
-              v18_res_ag_removal_reg(i2,kcr,attributes);
-
-
-*' In contrast to AG biomass, AG production `vm_res_biomass_ag(i,kcr,attributes)`
-*' is defined as the part of residues which is removed from the field. The
-*' difference between biomass and production is either burned on field or
-*' remains on the fields (either incorporated in soils or not) and decays.
-*' The field balance equations ensures that the production of AG residues
-*' `vm_res_biomass_ag(i,kcr,attributes)` is properly assigned to different uses:
-*' removal, on-field burning and recycling of AG residues.
-
- q18_res_field_balance(i2,kcr,attributes) ..
-                  vm_res_biomass_ag(i2,kcr,attributes)
-                  =e=
-                  v18_res_ag_removal_reg(i2,kcr,attributes)
-                  + vm_res_ag_burn(i2,kcr,attributes)
-                  + v18_res_ag_recycling(i2,kcr,attributes);
-
-*' make sure removal is less than biomass produced in each cluster
- q18_clust_field_constraint(j2,kres) ..
-             sum(kres_kcr(kres,kcr), v18_res_biomass_ag_clust(j2,kcr))
-              =g= 
-              v18_prod_res(j2, kres);
-
-*' The amount of residues burned on fields in a region `vm_res_ag_burn` is
-*' determined by the share (ic18_res_use_min_shr) of AG residue biomass.
-*' Based on @smil_nitrogen_1999, residue burning is fixed to 15% of total AG
-*' crop residue dry matter in developed and 25% in developing regions for each
-*' crop. For future time steps, these rates are scenario dependent, and either
-*' kept constant or reduced to 10% and 0% in 2050.
-
- q18_res_field_burn(i2,kcr,attributes) ..
-                  vm_res_ag_burn(i2,kcr,attributes)
-                  =e=
-                  sum(ct, im_development_state(ct,i2) * i18_res_use_burn(ct,"high_income",kcr)
-                  + (1-im_development_state(ct,i2)) * i18_res_use_burn(ct,"low_income",kcr))
-                  * vm_res_biomass_ag(i2,kcr,attributes);
-
-
-*' While the residue biomass is estimated with a crop-specific nutrient
-*' composition (which is required for consistent nutrient budgets), the
-*' removed residues are assumed to have homogeneous properties
-*' (to reduce the number of commodities in MAgPIE) within three crop residue
-*' groups (cereal straw, fibrous residues that cannot be digested
-*' by monogastrics, and non-fibrous residues that can be digested).
-*' The following constraint, in combination with the field balance equation,
-*' guarantees that mass balances are not violated while a homogeneous
-*' good is extracted from heterogeneous goods.
-
- q18_translate(j2,kres,attributes)..
-                  sum(kres_kcr(kres,kcr), v18_res_ag_removal(j2,kcr,attributes))
-                  =e=
-                  v18_prod_res(j2,kres) * fm_attributes(attributes,kres);
-
-*' sum to the regional amount of residues produced for the regional interface  
- q18_prod_res_reg(i2,kres)..
-                  vm_prod_reg(i2,kres)
-                  =e=
-                  sum(cell(i2,j2), v18_prod_res(j2,kres)) ;
-
-
-*' Residues recycled to croplands in nutrients `vm_res_recycling(i2,"nr")` are
-*' calculated based on the amount of AG residues left on field for recycling, the
-*' nutrients coming from burned residues, and on biomass that is left in
-*' BG residues. They are calculated to be transmitted to the nitrogen budget
-*' module [50_nr_soil_budget].
-
- q18_res_recycling_nr(i2) ..
-                  vm_res_recycling(i2,"nr")
-                  =e=
-                  sum(kcr, v18_res_ag_recycling(i2,kcr,"nr")
-                    + vm_res_ag_burn(i2,kcr,"nr")*(1-f18_res_combust_eff(kcr))
-                    + vm_res_biomass_bg(i2,kcr,"nr")
-                  );
-
-*' Similar to the recycled nutrients, the potash recycling is determined by the
-*' amount of AG residues with the potash content and the amounts of potash from
-*' burning residues. As P and K are not volatile and hardly water soluble, only
-*' removed aboveground crop residues have to be considered, while nutrients from
-*' burned AG as well as BG stay on the field.
-
- q18_res_recycling_pk(i2,pk18) ..
-                  vm_res_recycling(i2,pk18)
-                  =e=
-                  sum(kcr, 
-                    v18_res_ag_recycling(i2,kcr,pk18)
-                    + vm_res_ag_burn(i2,kcr,pk18)
-                  );
-
-*' Costs of residue harvest are based on straw baling and hauling from 
-*' Budynski, Stephanie. 2020. Straw Manufacturing in Alberta (@budynski_straw_2020), 
-*' using the lower range of the US costs.
-
- q18_cost_prod_res(i2,kres) ..
-                  vm_cost_prod_kres(i2,kres)
-                  =e=
-                  vm_prod_reg(i2,kres) * fm_attributes("wm",kres) *  f18_fac_req_kres(kres);
-
-*' Trade of AG residues is not considered, so that all produced AG residues have
-*' to be assigned to uses within the respective world region.
-
-
-*** EOF constraints.gms ***
diff --git a/modules/18_residues/flexcluster_jul23/postsolve.gms b/modules/18_residues/flexcluster_jul23/postsolve.gms
deleted file mode 100644
index 3593595ada..0000000000
--- a/modules/18_residues/flexcluster_jul23/postsolve.gms
+++ /dev/null
@@ -1,102 +0,0 @@
-*** |  (C) 2008-2025 Potsdam Institute for Climate Impact Research (PIK)
-*** |  authors, and contributors see CITATION.cff file. This file is part
-*** |  of MAgPIE and licensed under AGPL-3.0-or-later. Under Section 7 of
-*** |  AGPL-3.0, you are granted additional permissions described in the
-*** |  MAgPIE License Exception, version 1.0 (see LICENSE file).
-*** |  Contact: magpie@pik-potsdam.de
-
-****** Residues
-
-*** EOF postsolve.gms ***
-
-*#################### R SECTION START (OUTPUT DEFINITIONS) #####################
- ov18_prod_res(t,j,kres,"marginal")                     = v18_prod_res.m(j,kres);
- ov18_res_biomass_ag_clust(t,j,kcr,"marginal")          = v18_res_biomass_ag_clust.m(j,kcr);
- ov_res_biomass_ag(t,i,kcr,attributes,"marginal")       = vm_res_biomass_ag.m(i,kcr,attributes);
- ov_res_biomass_bg(t,i,kcr,dm_nr,"marginal")            = vm_res_biomass_bg.m(i,kcr,dm_nr);
- ov18_res_ag_removal(t,j,kcr,attributes,"marginal")     = v18_res_ag_removal.m(j,kcr,attributes);
- ov18_res_ag_removal_reg(t,i,kcr,attributes,"marginal") = v18_res_ag_removal_reg.m(i,kcr,attributes);
- ov18_res_ag_recycling(t,i,kcr,attributes,"marginal")   = v18_res_ag_recycling.m(i,kcr,attributes);
- ov_res_ag_burn(t,i,kcr,attributes,"marginal")          = vm_res_ag_burn.m(i,kcr,attributes);
- ov_res_recycling(t,i,npk,"marginal")                   = vm_res_recycling.m(i,npk);
- ov_cost_prod_kres(t,i,kres,"marginal")                 = vm_cost_prod_kres.m(i,kres);
- oq18_prod_res_ag_clust(t,j,kcr,"marginal")             = q18_prod_res_ag_clust.m(j,kcr);
- oq18_prod_res_ag_reg(t,i,kcr,attributes,"marginal")    = q18_prod_res_ag_reg.m(i,kcr,attributes);
- oq18_prod_res_bg_clust(t,i,kcr,dm_nr,"marginal")       = q18_prod_res_bg_clust.m(i,kcr,dm_nr);
- oq18_regional_removals(t,i,kcr,attributes,"marginal")  = q18_regional_removals.m(i,kcr,attributes);
- oq18_res_field_balance(t,i,kcr,attributes,"marginal")  = q18_res_field_balance.m(i,kcr,attributes);
- oq18_clust_field_constraint(t,j,kres,"marginal")       = q18_clust_field_constraint.m(j,kres);
- oq18_res_field_burn(t,i,kcr,attributes,"marginal")     = q18_res_field_burn.m(i,kcr,attributes);
- oq18_translate(t,j,kres,attributes,"marginal")         = q18_translate.m(j,kres,attributes);
- oq18_res_recycling_nr(t,i,"marginal")                  = q18_res_recycling_nr.m(i);
- oq18_res_recycling_pk(t,i,pk18,"marginal")             = q18_res_recycling_pk.m(i,pk18);
- oq18_cost_prod_res(t,i,kres,"marginal")                = q18_cost_prod_res.m(i,kres);
- oq18_prod_res_reg(t,i,kall,"marginal")                 = q18_prod_res_reg.m(i,kall);
- ov18_prod_res(t,j,kres,"level")                        = v18_prod_res.l(j,kres);
- ov18_res_biomass_ag_clust(t,j,kcr,"level")             = v18_res_biomass_ag_clust.l(j,kcr);
- ov_res_biomass_ag(t,i,kcr,attributes,"level")          = vm_res_biomass_ag.l(i,kcr,attributes);
- ov_res_biomass_bg(t,i,kcr,dm_nr,"level")               = vm_res_biomass_bg.l(i,kcr,dm_nr);
- ov18_res_ag_removal(t,j,kcr,attributes,"level")        = v18_res_ag_removal.l(j,kcr,attributes);
- ov18_res_ag_removal_reg(t,i,kcr,attributes,"level")    = v18_res_ag_removal_reg.l(i,kcr,attributes);
- ov18_res_ag_recycling(t,i,kcr,attributes,"level")      = v18_res_ag_recycling.l(i,kcr,attributes);
- ov_res_ag_burn(t,i,kcr,attributes,"level")             = vm_res_ag_burn.l(i,kcr,attributes);
- ov_res_recycling(t,i,npk,"level")                      = vm_res_recycling.l(i,npk);
- ov_cost_prod_kres(t,i,kres,"level")                    = vm_cost_prod_kres.l(i,kres);
- oq18_prod_res_ag_clust(t,j,kcr,"level")                = q18_prod_res_ag_clust.l(j,kcr);
- oq18_prod_res_ag_reg(t,i,kcr,attributes,"level")       = q18_prod_res_ag_reg.l(i,kcr,attributes);
- oq18_prod_res_bg_clust(t,i,kcr,dm_nr,"level")          = q18_prod_res_bg_clust.l(i,kcr,dm_nr);
- oq18_regional_removals(t,i,kcr,attributes,"level")     = q18_regional_removals.l(i,kcr,attributes);
- oq18_res_field_balance(t,i,kcr,attributes,"level")     = q18_res_field_balance.l(i,kcr,attributes);
- oq18_clust_field_constraint(t,j,kres,"level")          = q18_clust_field_constraint.l(j,kres);
- oq18_res_field_burn(t,i,kcr,attributes,"level")        = q18_res_field_burn.l(i,kcr,attributes);
- oq18_translate(t,j,kres,attributes,"level")            = q18_translate.l(j,kres,attributes);
- oq18_res_recycling_nr(t,i,"level")                     = q18_res_recycling_nr.l(i);
- oq18_res_recycling_pk(t,i,pk18,"level")                = q18_res_recycling_pk.l(i,pk18);
- oq18_cost_prod_res(t,i,kres,"level")                   = q18_cost_prod_res.l(i,kres);
- oq18_prod_res_reg(t,i,kall,"level")                    = q18_prod_res_reg.l(i,kall);
- ov18_prod_res(t,j,kres,"upper")                        = v18_prod_res.up(j,kres);
- ov18_res_biomass_ag_clust(t,j,kcr,"upper")             = v18_res_biomass_ag_clust.up(j,kcr);
- ov_res_biomass_ag(t,i,kcr,attributes,"upper")          = vm_res_biomass_ag.up(i,kcr,attributes);
- ov_res_biomass_bg(t,i,kcr,dm_nr,"upper")               = vm_res_biomass_bg.up(i,kcr,dm_nr);
- ov18_res_ag_removal(t,j,kcr,attributes,"upper")        = v18_res_ag_removal.up(j,kcr,attributes);
- ov18_res_ag_removal_reg(t,i,kcr,attributes,"upper")    = v18_res_ag_removal_reg.up(i,kcr,attributes);
- ov18_res_ag_recycling(t,i,kcr,attributes,"upper")      = v18_res_ag_recycling.up(i,kcr,attributes);
- ov_res_ag_burn(t,i,kcr,attributes,"upper")             = vm_res_ag_burn.up(i,kcr,attributes);
- ov_res_recycling(t,i,npk,"upper")                      = vm_res_recycling.up(i,npk);
- ov_cost_prod_kres(t,i,kres,"upper")                    = vm_cost_prod_kres.up(i,kres);
- oq18_prod_res_ag_clust(t,j,kcr,"upper")                = q18_prod_res_ag_clust.up(j,kcr);
- oq18_prod_res_ag_reg(t,i,kcr,attributes,"upper")       = q18_prod_res_ag_reg.up(i,kcr,attributes);
- oq18_prod_res_bg_clust(t,i,kcr,dm_nr,"upper")          = q18_prod_res_bg_clust.up(i,kcr,dm_nr);
- oq18_regional_removals(t,i,kcr,attributes,"upper")     = q18_regional_removals.up(i,kcr,attributes);
- oq18_res_field_balance(t,i,kcr,attributes,"upper")     = q18_res_field_balance.up(i,kcr,attributes);
- oq18_clust_field_constraint(t,j,kres,"upper")          = q18_clust_field_constraint.up(j,kres);
- oq18_res_field_burn(t,i,kcr,attributes,"upper")        = q18_res_field_burn.up(i,kcr,attributes);
- oq18_translate(t,j,kres,attributes,"upper")            = q18_translate.up(j,kres,attributes);
- oq18_res_recycling_nr(t,i,"upper")                     = q18_res_recycling_nr.up(i);
- oq18_res_recycling_pk(t,i,pk18,"upper")                = q18_res_recycling_pk.up(i,pk18);
- oq18_cost_prod_res(t,i,kres,"upper")                   = q18_cost_prod_res.up(i,kres);
- oq18_prod_res_reg(t,i,kall,"upper")                    = q18_prod_res_reg.up(i,kall);
- ov18_prod_res(t,j,kres,"lower")                        = v18_prod_res.lo(j,kres);
- ov18_res_biomass_ag_clust(t,j,kcr,"lower")             = v18_res_biomass_ag_clust.lo(j,kcr);
- ov_res_biomass_ag(t,i,kcr,attributes,"lower")          = vm_res_biomass_ag.lo(i,kcr,attributes);
- ov_res_biomass_bg(t,i,kcr,dm_nr,"lower")               = vm_res_biomass_bg.lo(i,kcr,dm_nr);
- ov18_res_ag_removal(t,j,kcr,attributes,"lower")        = v18_res_ag_removal.lo(j,kcr,attributes);
- ov18_res_ag_removal_reg(t,i,kcr,attributes,"lower")    = v18_res_ag_removal_reg.lo(i,kcr,attributes);
- ov18_res_ag_recycling(t,i,kcr,attributes,"lower")      = v18_res_ag_recycling.lo(i,kcr,attributes);
- ov_res_ag_burn(t,i,kcr,attributes,"lower")             = vm_res_ag_burn.lo(i,kcr,attributes);
- ov_res_recycling(t,i,npk,"lower")                      = vm_res_recycling.lo(i,npk);
- ov_cost_prod_kres(t,i,kres,"lower")                    = vm_cost_prod_kres.lo(i,kres);
- oq18_prod_res_ag_clust(t,j,kcr,"lower")                = q18_prod_res_ag_clust.lo(j,kcr);
- oq18_prod_res_ag_reg(t,i,kcr,attributes,"lower")       = q18_prod_res_ag_reg.lo(i,kcr,attributes);
- oq18_prod_res_bg_clust(t,i,kcr,dm_nr,"lower")          = q18_prod_res_bg_clust.lo(i,kcr,dm_nr);
- oq18_regional_removals(t,i,kcr,attributes,"lower")     = q18_regional_removals.lo(i,kcr,attributes);
- oq18_res_field_balance(t,i,kcr,attributes,"lower")     = q18_res_field_balance.lo(i,kcr,attributes);
- oq18_clust_field_constraint(t,j,kres,"lower")          = q18_clust_field_constraint.lo(j,kres);
- oq18_res_field_burn(t,i,kcr,attributes,"lower")        = q18_res_field_burn.lo(i,kcr,attributes);
- oq18_translate(t,j,kres,attributes,"lower")            = q18_translate.lo(j,kres,attributes);
- oq18_res_recycling_nr(t,i,"lower")                     = q18_res_recycling_nr.lo(i);
- oq18_res_recycling_pk(t,i,pk18,"lower")                = q18_res_recycling_pk.lo(i,pk18);
- oq18_cost_prod_res(t,i,kres,"lower")                   = q18_cost_prod_res.lo(i,kres);
- oq18_prod_res_reg(t,i,kall,"lower")                    = q18_prod_res_reg.lo(i,kall);
-*##################### R SECTION END (OUTPUT DEFINITIONS) ######################
-
diff --git a/modules/18_residues/flexreg_apr16/declarations.gms b/modules/18_residues/flexreg_apr16/declarations.gms
index e000474151..fa070b3196 100644
--- a/modules/18_residues/flexreg_apr16/declarations.gms
+++ b/modules/18_residues/flexreg_apr16/declarations.gms
@@ -8,54 +8,48 @@
 
 positive variables
  v18_prod_res(j,kres)                       Cellular production of residues (mio. tDM)
- vm_res_biomass_ag(i,kcr,attributes)        Production of aboveground residues in each region (mio. tDM)
- vm_res_biomass_bg(i,kcr,dm_nr)             Production of belowground residues in each region (mio. tDM)
- v18_res_ag_removal(i,kcr,attributes)       Removal of crop residues in respective attribute units DM GJ Nr P K WM C (mio. tX)
- v18_res_ag_recycling(i,kcr,attributes)     Recylcing of crop residues to soils in respective attribute units DM GJ Nr P K WM C (mio. tX)
- vm_res_ag_burn(i,kcr,attributes)           Residues burned on fields in respective attribute units DM GJ Nr P K WM C (mio. tX)
- vm_res_recycling(i,npk)                    Residues recycled to croplands in respective nutrients Nr P K units (mio. tX)
+ vm_res_biomass_ag(i,kcr,w,dm_cnr)      Production of aboveground residues in each region (mio. tDM)
+ vm_res_biomass_bg(i,kcr,w,dm_cnr)          Production of belowground residues in each region (mio. tDM)
+ v18_res_ag_removal(i,kcr,w,dm_cnr)     Removal of crop residues in respective attribute units DM GJ Nr P K WM C (mio. tX)
+ v18_res_ag_recycling(i,kcr,w,dm_cnr)   Recylcing of crop residues to soils in respective attribute units DM GJ Nr P K WM C (mio. tX)
+ vm_res_ag_burn(i,kcr,w,dm_cnr)         Residues burned on fields in respective attribute units DM GJ Nr P K WM C (mio. tX)
+ vm_res_recycling(i,kcr,w,dm_cnr)       Residues recycled to croplands in respective nutrients Nr P K units (mio. tX)
  vm_cost_prod_kres(i,kres)                  Production costs of harvesting crop residues (mio. USD17MER per yr)
 ;
 
 equations
-
- q18_prod_res_ag_reg(i,kcr,attributes)     Production constraint of aboveground residues (mio. tDM)
- q18_prod_res_bg_reg(i,kcr,dm_nr)          Production constraint of belowground residues (mio. tDM)
-
- q18_res_field_balance(i,kcr,attributes)   Calculation of the residues amount recycled to soils (mio. tDM)
- q18_res_field_burn(i,kcr,attributes)      Fixing of the residues amount burned in a region in respective attribute units DM GJ Nr P K WM C (mio. tX)
- q18_translate(i,kres,attributes)          Transformation of the multiple crop residues into supply balance crop redisues in respective attribute units DM GJ Nr P K WM C (mio. tX)
- q18_prod_res_cell(j,kres)                 Allows for distribution of residues to cellular level (mio. tDM)
-
- q18_res_recycling_nr(i)                   Nutrient recycling of reaactive nitrogen (mio. tNr)
- q18_res_recycling_pk(i,pk18)              Nutrient recycling of phosphorus and potash (mio. tX)
- q18_cost_prod_res(i,kres)                 Production costs of harvesting crop residues (mio. USD17MER)
-
+ q18_prod_res_ag_reg(i,kcr,w,dm_cnr)    Production constraint of aboveground residues (mio. tDM)
+ q18_prod_res_bg_reg(i,kcr,w,dm_cnr)        Production constraint of belowground residues (mio. tDM)
+ q18_res_field_balance(i,kcr,w,dm_cnr)  Calculation of the residues amount recycled to soils (mio. tDM)
+ q18_res_field_burn(i,kcr,w,dm_cnr)     Fixing of the residues amount burned in a region in respective attribute units DM GJ Nr P K WM C (mio. tX)
+ q18_translate(i,kres,dm_cnr)           Transformation of the multiple crop residues into supply balance crop redisues in respective attribute units DM GJ Nr P K WM C (mio. tX) 
+ q18_prod_res_reg(i,kres)                 Allows for distribution of residues to cellular level (mio. tDM)
+ q18_res_recycling_cnr(i,kcr,w,cnr)       Nutrient recycling of carbon and reaactive nitrogen (mio. tX)
+ q18_cost_prod_res(i,kres)                  Production costs of harvesting crop residues (mio. USD17MER)
 ;
 
 parameters
- i18_res_use_burn(t_all,dev18,kcr)         Share of residues burned on field (1)
+ i18_res_use_burn(t_all,dev18,kcr)          Share of residues burned on field (1)
 ;
 
 *#################### R SECTION START (OUTPUT DECLARATIONS) ####################
 parameters
- ov18_prod_res(t,j,kres,type)                    Cellular production of residues (mio. tDM)
- ov_res_biomass_ag(t,i,kcr,attributes,type)      Production of aboveground residues in each region (mio. tDM)
- ov_res_biomass_bg(t,i,kcr,dm_nr,type)           Production of belowground residues in each region (mio. tDM)
- ov18_res_ag_removal(t,i,kcr,attributes,type)    Removal of crop residues in respective attribute units DM GJ Nr P K WM C (mio. tX)
- ov18_res_ag_recycling(t,i,kcr,attributes,type)  Recylcing of crop residues to soils in respective attribute units DM GJ Nr P K WM C (mio. tX)
- ov_res_ag_burn(t,i,kcr,attributes,type)         Residues burned on fields in respective attribute units DM GJ Nr P K WM C (mio. tX)
- ov_res_recycling(t,i,npk,type)                  Residues recycled to croplands in respective nutrients Nr P K units (mio. tX)
- ov_cost_prod_kres(t,i,kres,type)                Production costs of harvesting crop residues (mio. USD17MER per yr)
- oq18_prod_res_ag_reg(t,i,kcr,attributes,type)   Production constraint of aboveground residues (mio. tDM)
- oq18_prod_res_bg_reg(t,i,kcr,dm_nr,type)        Production constraint of belowground residues (mio. tDM)
- oq18_res_field_balance(t,i,kcr,attributes,type) Calculation of the residues amount recycled to soils (mio. tDM)
- oq18_res_field_burn(t,i,kcr,attributes,type)    Fixing of the residues amount burned in a region in respective attribute units DM GJ Nr P K WM C (mio. tX)
- oq18_translate(t,i,kres,attributes,type)        Transformation of the multiple crop residues into supply balance crop redisues in respective attribute units DM GJ Nr P K WM C (mio. tX)
- oq18_prod_res_cell(t,j,kres,type)               Allows for distribution of residues to cellular level (mio. tDM)
- oq18_res_recycling_nr(t,i,type)                 Nutrient recycling of reaactive nitrogen (mio. tNr)
- oq18_res_recycling_pk(t,i,pk18,type)            Nutrient recycling of phosphorus and potash (mio. tX)
- oq18_cost_prod_res(t,i,kres,type)               Production costs of harvesting crop residues (mio. USD17MER)
+ ov18_prod_res(t,j,kres,type)                  Cellular production of residues (mio. tDM)
+ ov_res_biomass_ag(t,i,kcr,w,dm_cnr,type)      Production of aboveground residues in each region (mio. tDM)
+ ov_res_biomass_bg(t,i,kcr,w,dm_cnr,type)      Production of belowground residues in each region (mio. tDM)
+ ov18_res_ag_removal(t,i,kcr,w,dm_cnr,type)    Removal of crop residues in respective attribute units DM GJ Nr P K WM C (mio. tX)
+ ov18_res_ag_recycling(t,i,kcr,w,dm_cnr,type)  Recylcing of crop residues to soils in respective attribute units DM GJ Nr P K WM C (mio. tX)
+ ov_res_ag_burn(t,i,kcr,w,dm_cnr,type)         Residues burned on fields in respective attribute units DM GJ Nr P K WM C (mio. tX)
+ ov_res_recycling(t,i,kcr,w,dm_cnr,type)       Residues recycled to croplands in respective nutrients Nr P K units (mio. tX)
+ ov_cost_prod_kres(t,i,kres,type)              Production costs of harvesting crop residues (mio. USD17MER per yr)
+ oq18_prod_res_ag_reg(t,i,kcr,w,dm_cnr,type)   Production constraint of aboveground residues (mio. tDM)
+ oq18_prod_res_bg_reg(t,i,kcr,w,dm_cnr,type)   Production constraint of belowground residues (mio. tDM)
+ oq18_res_field_balance(t,i,kcr,w,dm_cnr,type) Calculation of the residues amount recycled to soils (mio. tDM)
+ oq18_res_field_burn(t,i,kcr,w,dm_cnr,type)    Fixing of the residues amount burned in a region in respective attribute units DM GJ Nr P K WM C (mio. tX)
+ oq18_translate(t,i,kres,dm_cnr,type)          Transformation of the multiple crop residues into supply balance crop redisues in respective attribute units DM GJ Nr P K WM C (mio. tX)
+ oq18_prod_res_reg(t,i,kres,type)              Allows for distribution of residues to cellular level (mio. tDM)
+ oq18_res_recycling_cnr(t,i,kcr,w,cnr,type)    Nutrient recycling of carbon and reaactive nitrogen (mio. tX)
+ oq18_cost_prod_res(t,i,kres,type)             Production costs of harvesting crop residues (mio. USD17MER)
 ;
 *##################### R SECTION END (OUTPUT DECLARATIONS) #####################
 
diff --git a/modules/18_residues/flexreg_apr16/equations.gms b/modules/18_residues/flexreg_apr16/equations.gms
index e01b0d2072..57c38e0cbb 100644
--- a/modules/18_residues/flexreg_apr16/equations.gms
+++ b/modules/18_residues/flexreg_apr16/equations.gms
@@ -11,36 +11,37 @@
 *' of harvested area `vm_area` and production `vm_prod_reg`. `f18_cgf` contains
 *' slope and intercept parameters of the CGFs.
 
- q18_prod_res_ag_reg(i2,kcr,attributes) ..
-                 vm_res_biomass_ag(i2,kcr,attributes)
+ q18_prod_res_ag_reg(i2,kcr,w,dm_cnr) ..
+                 vm_res_biomass_ag(i2,kcr,w,dm_cnr)
                  =e=
-                 (sum((cell(i2,j2),w), vm_area(j2,kcr,w)) * sum(ct,f18_multicropping(ct,i2)) * f18_cgf("intercept",kcr)
-                 + vm_prod_reg(i2,kcr) * f18_cgf("slope",kcr))
-                 * f18_attributes_residue_ag(attributes,kcr);
+                 (sum(cell(i2,j2), vm_area(j2,kcr,w)) * sum(ct,f18_multicropping(ct,i2)) * f18_cgf("intercept",kcr)
+                   + sum(cell(i2,j2), vm_prod_kcr_w(j2,kcr,w)) * f18_cgf("slope",kcr))
+                 * f18_attributes_residue_ag(dm_cnr,kcr);
 
 *' The BG crop residue biomass `vm_res_biomass_bg` is calculated as a function of
 *' total aboveground biomass.
 
- q18_prod_res_bg_reg(i2,kcr,dm_nr) ..
-                 vm_res_biomass_bg(i2,kcr,dm_nr)
+ q18_prod_res_bg_reg(i2,kcr,w,dm_cnr) ..
+                 vm_res_biomass_bg(i2,kcr,w,dm_cnr)
                  =e=
-                 (vm_prod_reg(i2,kcr) + vm_res_biomass_ag(i2,kcr,"dm")) * f18_cgf("bg_to_ag",kcr)
-                 * f18_attributes_residue_bg(dm_nr,kcr);
+                 (sum(cell(i2,j2), vm_prod_kcr_w(j2,kcr,w)) +   
+                   vm_res_biomass_ag(i2,kcr,w,"dm")) * f18_cgf("bg_to_ag",kcr)
+                 * f18_attributes_residue_bg(dm_cnr,kcr);
 
-*' In contrast to AG biomass, AG production `vm_res_biomass_ag(i,kcr,attributes)`
+*' In contrast to AG biomass, AG production `vm_res_biomass_ag(i,kcr,w,dm_cnr)`
 *' is defined as the part of residues which is removed from the field. The
 *' difference between biomass and production is either burned on field or
 *' remains on the fields (either incorporated in soils or not) and decays.
 *' The field balance equations ensures that the production of AG residues
-*' `vm_res_biomass_ag(i,kcr,attributes)` is properly assigned to different uses:
+*' `vm_res_biomass_ag(i,kcr,w,dm_cnr)` is properly assigned to different uses:
 *' removal, on-field burning and recycling of AG residues.
 
- q18_res_field_balance(i2,kcr,attributes) ..
-                  vm_res_biomass_ag(i2,kcr,attributes)
+ q18_res_field_balance(i2,kcr,w,dm_cnr) ..
+                  vm_res_biomass_ag(i2,kcr,w,dm_cnr)
                   =e=
-                  v18_res_ag_removal(i2,kcr,attributes)
-                  + vm_res_ag_burn(i2,kcr,attributes)
-                  + v18_res_ag_recycling(i2,kcr,attributes);
+                  v18_res_ag_removal(i2,kcr,w,dm_cnr)
+                  + vm_res_ag_burn(i2,kcr,w,dm_cnr)
+                  + v18_res_ag_recycling(i2,kcr,w,dm_cnr);
 
 *' The amount of residues burned on fields in a region `vm_res_ag_burn` is
 *' determined by the share (ic18_res_use_min_shr) of AG residue biomass.
@@ -49,12 +50,12 @@
 *' crop. For future time steps, these rates are scenario dependent, and either
 *' kept constant or reduced to 10% and 0% in 2050.
 
- q18_res_field_burn(i2,kcr,attributes) ..
-                  vm_res_ag_burn(i2,kcr,attributes)
+ q18_res_field_burn(i2,kcr,w,dm_cnr) ..
+                  vm_res_ag_burn(i2,kcr,w,dm_cnr)
                   =e=
                   sum(ct, im_development_state(ct,i2) * i18_res_use_burn(ct,"high_income",kcr)
                   + (1-im_development_state(ct,i2)) * i18_res_use_burn(ct,"low_income",kcr))
-                  * vm_res_biomass_ag(i2,kcr,attributes);
+                  * vm_res_biomass_ag(i2,kcr,w,dm_cnr);
 
 
 *' While the residue biomass is estiamted with a crop-specific nutrient
@@ -67,17 +68,18 @@
 *' guarantees that mass balances are not violated while a homogeneous
 *' good is extracted from heterogeneous goods.
 
- q18_translate(i2,kres,attributes)..
-                  sum(kres_kcr(kres,kcr), v18_res_ag_removal(i2,kcr,attributes))
+
+ q18_translate(i2,kres,dm_cnr)..
+                  sum((kres_kcr(kres,kcr),w), v18_res_ag_removal(i2,kcr,w,dm_cnr))
                   =e=
-                  vm_prod_reg(i2,kres) * fm_attributes(attributes,kres);
+                  vm_prod_reg(i2,kres) * fm_attributes(dm_cnr,kres);
 
 *' Amount produced at cellular level is flexible, can be distributed as it wants 
- q18_prod_res_cell(j2,kres)..
-                  sum(cell(i2,j2), vm_prod_reg(i2,kres))
-                  =e=
-                  v18_prod_res(j2,kres) ;
 
+ q18_prod_res_reg(i2,kres)..
+                  sum(cell(i2,j2), v18_prod_res(j2,kres))
+                  =e=
+                  vm_prod_reg(i2,kres);
 
 *' Residues recycled to croplands in nutrients `vm_res_recycling(i2,"nr")` are
 *' calcualted based on the amount of AG residues left on field for recycling, the
@@ -85,27 +87,13 @@
 *' BG residues. They are calculated to be transmitted to the nitrogen budget
 *' module [50_nr_soil_budget].
 
- q18_res_recycling_nr(i2) ..
-                  vm_res_recycling(i2,"nr")
-                  =e=
-                  sum(kcr,  v18_res_ag_recycling(i2,kcr,"nr")
-                    + vm_res_ag_burn(i2,kcr,"nr")*(1-f18_res_combust_eff(kcr))
-                    + vm_res_biomass_bg(i2,kcr,"nr")
-                  );
-
-*' Similar to the recycled nutrients, the potash recycling is determined by the
-*' amount of AG residues with the potash content and the amounts of potash from
-*' burning residues. As P and K are not volatile and hardly water soluble, only
-*' removed aboveground crop residues have to be considered, while nutrients from
-*' burned AG as well as BG stay on the field.
-
- q18_res_recycling_pk(i2,pk18) ..
-                  vm_res_recycling(i2,pk18)
+ q18_res_recycling_cnr(i2,kcr,w,cnr) ..
+                  vm_res_recycling(i2,kcr,w,cnr)
                   =e=
-                  sum(kcr,
-                    v18_res_ag_recycling(i2,kcr,pk18)
-                    + vm_res_ag_burn(i2,kcr,pk18)
-                  );
+                  v18_res_ag_recycling(i2,kcr,w,cnr)
+                    + vm_res_ag_burn(i2,kcr,w,cnr)*(1-f18_res_combust_eff(kcr))
+                    + vm_res_biomass_bg(i2,kcr,w,cnr)
+                  ;
 
 *' Costs of residue harvest are based on straw baling and hauling from 
 *' Budynski, Stephanie. 2020. Straw Manufacturing in Alberta (@budynski_straw_2020), 
@@ -114,7 +102,7 @@
  q18_cost_prod_res(i2,kres) ..
                   vm_cost_prod_kres(i2,kres)
                   =e=
-                  vm_prod_reg(i2,kres) * fm_attributes("wm",kres) *  f18_fac_req_kres(kres);
+                  vm_prod_reg(i2,kres) * fm_attributes("wm",kres)  *  f18_fac_req_kres(kres);
 
 *' Trade of AG residues is not considered, so that all produced AG residues have
 *' to be assigned to uses within the respective world region.
diff --git a/modules/18_residues/flexreg_apr16/input.gms b/modules/18_residues/flexreg_apr16/input.gms
index b6c23e24f1..f45820cc55 100644
--- a/modules/18_residues/flexreg_apr16/input.gms
+++ b/modules/18_residues/flexreg_apr16/input.gms
@@ -19,7 +19,7 @@ $include "./modules/18_residues/input/f18_attributes_residue_ag.csv"
 $offdelim;
 
 
-table f18_attributes_residue_bg(dm_nr,kve) Nutrient content of belowground crop residues in reactive nitorgen and carbon units Nr C (X per DM)
+table f18_attributes_residue_bg(dm_cnr,kve) Nutrient content of belowground crop residues in reactive nitorgen and carbon units Nr C (X per DM)
 $ondelim
 $include "./modules/18_residues/input/f18_attributes_residue_bg.csv"
 $offdelim;
diff --git a/modules/18_residues/flexreg_apr16/not_used.txt b/modules/18_residues/flexreg_apr16/not_used.txt
deleted file mode 100644
index 07cb618a78..0000000000
--- a/modules/18_residues/flexreg_apr16/not_used.txt
+++ /dev/null
@@ -1,2 +0,0 @@
-name,type,reason
-vm_prod,input,not needed
\ No newline at end of file
diff --git a/modules/18_residues/flexreg_apr16/postsolve.gms b/modules/18_residues/flexreg_apr16/postsolve.gms
index 0b0007332b..8aa7ee916e 100644
--- a/modules/18_residues/flexreg_apr16/postsolve.gms
+++ b/modules/18_residues/flexreg_apr16/postsolve.gms
@@ -10,73 +10,69 @@
 *** EOF postsolve.gms ***
 
 *#################### R SECTION START (OUTPUT DEFINITIONS) #####################
- ov18_prod_res(t,j,kres,"marginal")                    = v18_prod_res.m(j,kres);
- ov_res_biomass_ag(t,i,kcr,attributes,"marginal")      = vm_res_biomass_ag.m(i,kcr,attributes);
- ov_res_biomass_bg(t,i,kcr,dm_nr,"marginal")           = vm_res_biomass_bg.m(i,kcr,dm_nr);
- ov18_res_ag_removal(t,i,kcr,attributes,"marginal")    = v18_res_ag_removal.m(i,kcr,attributes);
- ov18_res_ag_recycling(t,i,kcr,attributes,"marginal")  = v18_res_ag_recycling.m(i,kcr,attributes);
- ov_res_ag_burn(t,i,kcr,attributes,"marginal")         = vm_res_ag_burn.m(i,kcr,attributes);
- ov_res_recycling(t,i,npk,"marginal")                  = vm_res_recycling.m(i,npk);
- ov_cost_prod_kres(t,i,kres,"marginal")                = vm_cost_prod_kres.m(i,kres);
- oq18_prod_res_ag_reg(t,i,kcr,attributes,"marginal")   = q18_prod_res_ag_reg.m(i,kcr,attributes);
- oq18_prod_res_bg_reg(t,i,kcr,dm_nr,"marginal")        = q18_prod_res_bg_reg.m(i,kcr,dm_nr);
- oq18_res_field_balance(t,i,kcr,attributes,"marginal") = q18_res_field_balance.m(i,kcr,attributes);
- oq18_res_field_burn(t,i,kcr,attributes,"marginal")    = q18_res_field_burn.m(i,kcr,attributes);
- oq18_translate(t,i,kres,attributes,"marginal")        = q18_translate.m(i,kres,attributes);
- oq18_prod_res_cell(t,j,kres,"marginal")               = q18_prod_res_cell.m(j,kres);
- oq18_res_recycling_nr(t,i,"marginal")                 = q18_res_recycling_nr.m(i);
- oq18_res_recycling_pk(t,i,pk18,"marginal")            = q18_res_recycling_pk.m(i,pk18);
- oq18_cost_prod_res(t,i,kres,"marginal")               = q18_cost_prod_res.m(i,kres);
- ov18_prod_res(t,j,kres,"level")                       = v18_prod_res.l(j,kres);
- ov_res_biomass_ag(t,i,kcr,attributes,"level")         = vm_res_biomass_ag.l(i,kcr,attributes);
- ov_res_biomass_bg(t,i,kcr,dm_nr,"level")              = vm_res_biomass_bg.l(i,kcr,dm_nr);
- ov18_res_ag_removal(t,i,kcr,attributes,"level")       = v18_res_ag_removal.l(i,kcr,attributes);
- ov18_res_ag_recycling(t,i,kcr,attributes,"level")     = v18_res_ag_recycling.l(i,kcr,attributes);
- ov_res_ag_burn(t,i,kcr,attributes,"level")            = vm_res_ag_burn.l(i,kcr,attributes);
- ov_res_recycling(t,i,npk,"level")                     = vm_res_recycling.l(i,npk);
- ov_cost_prod_kres(t,i,kres,"level")                   = vm_cost_prod_kres.l(i,kres);
- oq18_prod_res_ag_reg(t,i,kcr,attributes,"level")      = q18_prod_res_ag_reg.l(i,kcr,attributes);
- oq18_prod_res_bg_reg(t,i,kcr,dm_nr,"level")           = q18_prod_res_bg_reg.l(i,kcr,dm_nr);
- oq18_res_field_balance(t,i,kcr,attributes,"level")    = q18_res_field_balance.l(i,kcr,attributes);
- oq18_res_field_burn(t,i,kcr,attributes,"level")       = q18_res_field_burn.l(i,kcr,attributes);
- oq18_translate(t,i,kres,attributes,"level")           = q18_translate.l(i,kres,attributes);
- oq18_prod_res_cell(t,j,kres,"level")                  = q18_prod_res_cell.l(j,kres);
- oq18_res_recycling_nr(t,i,"level")                    = q18_res_recycling_nr.l(i);
- oq18_res_recycling_pk(t,i,pk18,"level")               = q18_res_recycling_pk.l(i,pk18);
- oq18_cost_prod_res(t,i,kres,"level")                  = q18_cost_prod_res.l(i,kres);
- ov18_prod_res(t,j,kres,"upper")                       = v18_prod_res.up(j,kres);
- ov_res_biomass_ag(t,i,kcr,attributes,"upper")         = vm_res_biomass_ag.up(i,kcr,attributes);
- ov_res_biomass_bg(t,i,kcr,dm_nr,"upper")              = vm_res_biomass_bg.up(i,kcr,dm_nr);
- ov18_res_ag_removal(t,i,kcr,attributes,"upper")       = v18_res_ag_removal.up(i,kcr,attributes);
- ov18_res_ag_recycling(t,i,kcr,attributes,"upper")     = v18_res_ag_recycling.up(i,kcr,attributes);
- ov_res_ag_burn(t,i,kcr,attributes,"upper")            = vm_res_ag_burn.up(i,kcr,attributes);
- ov_res_recycling(t,i,npk,"upper")                     = vm_res_recycling.up(i,npk);
- ov_cost_prod_kres(t,i,kres,"upper")                   = vm_cost_prod_kres.up(i,kres);
- oq18_prod_res_ag_reg(t,i,kcr,attributes,"upper")      = q18_prod_res_ag_reg.up(i,kcr,attributes);
- oq18_prod_res_bg_reg(t,i,kcr,dm_nr,"upper")           = q18_prod_res_bg_reg.up(i,kcr,dm_nr);
- oq18_res_field_balance(t,i,kcr,attributes,"upper")    = q18_res_field_balance.up(i,kcr,attributes);
- oq18_res_field_burn(t,i,kcr,attributes,"upper")       = q18_res_field_burn.up(i,kcr,attributes);
- oq18_translate(t,i,kres,attributes,"upper")           = q18_translate.up(i,kres,attributes);
- oq18_prod_res_cell(t,j,kres,"upper")                  = q18_prod_res_cell.up(j,kres);
- oq18_res_recycling_nr(t,i,"upper")                    = q18_res_recycling_nr.up(i);
- oq18_res_recycling_pk(t,i,pk18,"upper")               = q18_res_recycling_pk.up(i,pk18);
- oq18_cost_prod_res(t,i,kres,"upper")                  = q18_cost_prod_res.up(i,kres);
- ov18_prod_res(t,j,kres,"lower")                       = v18_prod_res.lo(j,kres);
- ov_res_biomass_ag(t,i,kcr,attributes,"lower")         = vm_res_biomass_ag.lo(i,kcr,attributes);
- ov_res_biomass_bg(t,i,kcr,dm_nr,"lower")              = vm_res_biomass_bg.lo(i,kcr,dm_nr);
- ov18_res_ag_removal(t,i,kcr,attributes,"lower")       = v18_res_ag_removal.lo(i,kcr,attributes);
- ov18_res_ag_recycling(t,i,kcr,attributes,"lower")     = v18_res_ag_recycling.lo(i,kcr,attributes);
- ov_res_ag_burn(t,i,kcr,attributes,"lower")            = vm_res_ag_burn.lo(i,kcr,attributes);
- ov_res_recycling(t,i,npk,"lower")                     = vm_res_recycling.lo(i,npk);
- ov_cost_prod_kres(t,i,kres,"lower")                   = vm_cost_prod_kres.lo(i,kres);
- oq18_prod_res_ag_reg(t,i,kcr,attributes,"lower")      = q18_prod_res_ag_reg.lo(i,kcr,attributes);
- oq18_prod_res_bg_reg(t,i,kcr,dm_nr,"lower")           = q18_prod_res_bg_reg.lo(i,kcr,dm_nr);
- oq18_res_field_balance(t,i,kcr,attributes,"lower")    = q18_res_field_balance.lo(i,kcr,attributes);
- oq18_res_field_burn(t,i,kcr,attributes,"lower")       = q18_res_field_burn.lo(i,kcr,attributes);
- oq18_translate(t,i,kres,attributes,"lower")           = q18_translate.lo(i,kres,attributes);
- oq18_prod_res_cell(t,j,kres,"lower")                  = q18_prod_res_cell.lo(j,kres);
- oq18_res_recycling_nr(t,i,"lower")                    = q18_res_recycling_nr.lo(i);
- oq18_res_recycling_pk(t,i,pk18,"lower")               = q18_res_recycling_pk.lo(i,pk18);
- oq18_cost_prod_res(t,i,kres,"lower")                  = q18_cost_prod_res.lo(i,kres);
+ ov18_prod_res(t,j,kres,"marginal")                  = v18_prod_res.m(j,kres);
+ ov_res_biomass_ag(t,i,kcr,w,dm_cnr,"marginal")      = vm_res_biomass_ag.m(i,kcr,w,dm_cnr);
+ ov_res_biomass_bg(t,i,kcr,w,dm_cnr,"marginal")      = vm_res_biomass_bg.m(i,kcr,w,dm_cnr);
+ ov18_res_ag_removal(t,i,kcr,w,dm_cnr,"marginal")    = v18_res_ag_removal.m(i,kcr,w,dm_cnr);
+ ov18_res_ag_recycling(t,i,kcr,w,dm_cnr,"marginal")  = v18_res_ag_recycling.m(i,kcr,w,dm_cnr);
+ ov_res_ag_burn(t,i,kcr,w,dm_cnr,"marginal")         = vm_res_ag_burn.m(i,kcr,w,dm_cnr);
+ ov_res_recycling(t,i,kcr,w,dm_cnr,"marginal")       = vm_res_recycling.m(i,kcr,w,dm_cnr);
+ ov_cost_prod_kres(t,i,kres,"marginal")              = vm_cost_prod_kres.m(i,kres);
+ oq18_prod_res_ag_reg(t,i,kcr,w,dm_cnr,"marginal")   = q18_prod_res_ag_reg.m(i,kcr,w,dm_cnr);
+ oq18_prod_res_bg_reg(t,i,kcr,w,dm_cnr,"marginal")   = q18_prod_res_bg_reg.m(i,kcr,w,dm_cnr);
+ oq18_res_field_balance(t,i,kcr,w,dm_cnr,"marginal") = q18_res_field_balance.m(i,kcr,w,dm_cnr);
+ oq18_res_field_burn(t,i,kcr,w,dm_cnr,"marginal")    = q18_res_field_burn.m(i,kcr,w,dm_cnr);
+ oq18_translate(t,i,kres,dm_cnr,"marginal")          = q18_translate.m(i,kres,dm_cnr);
+ oq18_prod_res_reg(t,i,kres,"marginal")              = q18_prod_res_reg.m(i,kres);
+ oq18_res_recycling_cnr(t,i,kcr,w,cnr,"marginal")    = q18_res_recycling_cnr.m(i,kcr,w,cnr);
+ oq18_cost_prod_res(t,i,kres,"marginal")             = q18_cost_prod_res.m(i,kres);
+ ov18_prod_res(t,j,kres,"level")                     = v18_prod_res.l(j,kres);
+ ov_res_biomass_ag(t,i,kcr,w,dm_cnr,"level")         = vm_res_biomass_ag.l(i,kcr,w,dm_cnr);
+ ov_res_biomass_bg(t,i,kcr,w,dm_cnr,"level")         = vm_res_biomass_bg.l(i,kcr,w,dm_cnr);
+ ov18_res_ag_removal(t,i,kcr,w,dm_cnr,"level")       = v18_res_ag_removal.l(i,kcr,w,dm_cnr);
+ ov18_res_ag_recycling(t,i,kcr,w,dm_cnr,"level")     = v18_res_ag_recycling.l(i,kcr,w,dm_cnr);
+ ov_res_ag_burn(t,i,kcr,w,dm_cnr,"level")            = vm_res_ag_burn.l(i,kcr,w,dm_cnr);
+ ov_res_recycling(t,i,kcr,w,dm_cnr,"level")          = vm_res_recycling.l(i,kcr,w,dm_cnr);
+ ov_cost_prod_kres(t,i,kres,"level")                 = vm_cost_prod_kres.l(i,kres);
+ oq18_prod_res_ag_reg(t,i,kcr,w,dm_cnr,"level")      = q18_prod_res_ag_reg.l(i,kcr,w,dm_cnr);
+ oq18_prod_res_bg_reg(t,i,kcr,w,dm_cnr,"level")      = q18_prod_res_bg_reg.l(i,kcr,w,dm_cnr);
+ oq18_res_field_balance(t,i,kcr,w,dm_cnr,"level")    = q18_res_field_balance.l(i,kcr,w,dm_cnr);
+ oq18_res_field_burn(t,i,kcr,w,dm_cnr,"level")       = q18_res_field_burn.l(i,kcr,w,dm_cnr);
+ oq18_translate(t,i,kres,dm_cnr,"level")             = q18_translate.l(i,kres,dm_cnr);
+ oq18_prod_res_reg(t,i,kres,"level")                 = q18_prod_res_reg.l(i,kres);
+ oq18_res_recycling_cnr(t,i,kcr,w,cnr,"level")       = q18_res_recycling_cnr.l(i,kcr,w,cnr);
+ oq18_cost_prod_res(t,i,kres,"level")                = q18_cost_prod_res.l(i,kres);
+ ov18_prod_res(t,j,kres,"upper")                     = v18_prod_res.up(j,kres);
+ ov_res_biomass_ag(t,i,kcr,w,dm_cnr,"upper")         = vm_res_biomass_ag.up(i,kcr,w,dm_cnr);
+ ov_res_biomass_bg(t,i,kcr,w,dm_cnr,"upper")         = vm_res_biomass_bg.up(i,kcr,w,dm_cnr);
+ ov18_res_ag_removal(t,i,kcr,w,dm_cnr,"upper")       = v18_res_ag_removal.up(i,kcr,w,dm_cnr);
+ ov18_res_ag_recycling(t,i,kcr,w,dm_cnr,"upper")     = v18_res_ag_recycling.up(i,kcr,w,dm_cnr);
+ ov_res_ag_burn(t,i,kcr,w,dm_cnr,"upper")            = vm_res_ag_burn.up(i,kcr,w,dm_cnr);
+ ov_res_recycling(t,i,kcr,w,dm_cnr,"upper")          = vm_res_recycling.up(i,kcr,w,dm_cnr);
+ ov_cost_prod_kres(t,i,kres,"upper")                 = vm_cost_prod_kres.up(i,kres);
+ oq18_prod_res_ag_reg(t,i,kcr,w,dm_cnr,"upper")      = q18_prod_res_ag_reg.up(i,kcr,w,dm_cnr);
+ oq18_prod_res_bg_reg(t,i,kcr,w,dm_cnr,"upper")      = q18_prod_res_bg_reg.up(i,kcr,w,dm_cnr);
+ oq18_res_field_balance(t,i,kcr,w,dm_cnr,"upper")    = q18_res_field_balance.up(i,kcr,w,dm_cnr);
+ oq18_res_field_burn(t,i,kcr,w,dm_cnr,"upper")       = q18_res_field_burn.up(i,kcr,w,dm_cnr);
+ oq18_translate(t,i,kres,dm_cnr,"upper")             = q18_translate.up(i,kres,dm_cnr);
+ oq18_prod_res_reg(t,i,kres,"upper")                 = q18_prod_res_reg.up(i,kres);
+ oq18_res_recycling_cnr(t,i,kcr,w,cnr,"upper")       = q18_res_recycling_cnr.up(i,kcr,w,cnr);
+ oq18_cost_prod_res(t,i,kres,"upper")                = q18_cost_prod_res.up(i,kres);
+ ov18_prod_res(t,j,kres,"lower")                     = v18_prod_res.lo(j,kres);
+ ov_res_biomass_ag(t,i,kcr,w,dm_cnr,"lower")         = vm_res_biomass_ag.lo(i,kcr,w,dm_cnr);
+ ov_res_biomass_bg(t,i,kcr,w,dm_cnr,"lower")         = vm_res_biomass_bg.lo(i,kcr,w,dm_cnr);
+ ov18_res_ag_removal(t,i,kcr,w,dm_cnr,"lower")       = v18_res_ag_removal.lo(i,kcr,w,dm_cnr);
+ ov18_res_ag_recycling(t,i,kcr,w,dm_cnr,"lower")     = v18_res_ag_recycling.lo(i,kcr,w,dm_cnr);
+ ov_res_ag_burn(t,i,kcr,w,dm_cnr,"lower")            = vm_res_ag_burn.lo(i,kcr,w,dm_cnr);
+ ov_res_recycling(t,i,kcr,w,dm_cnr,"lower")          = vm_res_recycling.lo(i,kcr,w,dm_cnr);
+ ov_cost_prod_kres(t,i,kres,"lower")                 = vm_cost_prod_kres.lo(i,kres);
+ oq18_prod_res_ag_reg(t,i,kcr,w,dm_cnr,"lower")      = q18_prod_res_ag_reg.lo(i,kcr,w,dm_cnr);
+ oq18_prod_res_bg_reg(t,i,kcr,w,dm_cnr,"lower")      = q18_prod_res_bg_reg.lo(i,kcr,w,dm_cnr);
+ oq18_res_field_balance(t,i,kcr,w,dm_cnr,"lower")    = q18_res_field_balance.lo(i,kcr,w,dm_cnr);
+ oq18_res_field_burn(t,i,kcr,w,dm_cnr,"lower")       = q18_res_field_burn.lo(i,kcr,w,dm_cnr);
+ oq18_translate(t,i,kres,dm_cnr,"lower")             = q18_translate.lo(i,kres,dm_cnr);
+ oq18_prod_res_reg(t,i,kres,"lower")                 = q18_prod_res_reg.lo(i,kres);
+ oq18_res_recycling_cnr(t,i,kcr,w,cnr,"lower")       = q18_res_recycling_cnr.lo(i,kcr,w,cnr);
+ oq18_cost_prod_res(t,i,kres,"lower")                = q18_cost_prod_res.lo(i,kres);
 *##################### R SECTION END (OUTPUT DEFINITIONS) ######################
 
diff --git a/modules/18_residues/flexreg_apr16/presolve.gms b/modules/18_residues/flexreg_apr16/presolve.gms
index e30abe7706..99b4fedd49 100644
--- a/modules/18_residues/flexreg_apr16/presolve.gms
+++ b/modules/18_residues/flexreg_apr16/presolve.gms
@@ -5,6 +5,6 @@
 *** |  MAgPIE License Exception, version 1.0 (see LICENSE file).
 *** |  Contact: magpie@pik-potsdam.de
 
-v18_res_ag_removal.fx(i,nonused18,attributes)=0;
+v18_res_ag_removal.fx(i,nonused18,w,dm_cnr)=0;
 
 *** EOF solve.gms ***
diff --git a/modules/18_residues/flexreg_apr16/sets.gms b/modules/18_residues/flexreg_apr16/sets.gms
index d7f8b76c4c..74b6032e54 100644
--- a/modules/18_residues/flexreg_apr16/sets.gms
+++ b/modules/18_residues/flexreg_apr16/sets.gms
@@ -8,11 +8,11 @@
 
 sets
 
-dm_nr(attributes) dry matter and nr
+dm_cnr(attributes) dry matter carbon and nr
 /dm, nr, c/
 
-pk18(npk) subset of npk containing P and K nutrients
-/p, k/
+cnr(dm_cnr) carbon and nr
+/nr, c/
 
 dev18 country develoment indicator
 /high_income,low_income/
diff --git a/modules/18_residues/module.gms b/modules/18_residues/module.gms
index f44727ae6f..c7c29bbfaa 100644
--- a/modules/18_residues/module.gms
+++ b/modules/18_residues/module.gms
@@ -17,7 +17,7 @@
 *' @authors Benjamin Leon Bodirsky
 
 *###################### R SECTION START (MODULETYPES) ##########################
-$Ifi "%residues%" == "flexcluster_jul23" $include "./modules/18_residues/flexcluster_jul23/realization.gms"
+$Ifi "%residues%" == "disaggRes_apr25" $include "./modules/18_residues/disaggRes_apr25/realization.gms"
 $Ifi "%residues%" == "flexreg_apr16" $include "./modules/18_residues/flexreg_apr16/realization.gms"
 $Ifi "%residues%" == "off" $include "./modules/18_residues/off/realization.gms"
 *###################### R SECTION END (MODULETYPES) ############################
diff --git a/modules/18_residues/off/declarations.gms b/modules/18_residues/off/declarations.gms
index 8e99f755b8..c04ed7bb36 100644
--- a/modules/18_residues/off/declarations.gms
+++ b/modules/18_residues/off/declarations.gms
@@ -7,21 +7,21 @@
 
 
 positive variables
- vm_res_biomass_ag(i,kcr,attributes)                   production of aboveground residues in each region (mio. tDM)
- vm_res_biomass_bg(i,kcr,dm_nr)                        production of belowground residues in each region (mio. tDM)
- vm_res_recycling(i,npk)                               residues recycled to croplands (mio tons nutrients)
- vm_res_ag_burn(i,kcr,attributes)                      Residues burned on fields in respective attribute units DM GJ Nr P K WM C (mio. tX)
+ vm_res_biomass_ag(i,kcr,w,dm_cnr)                 production of aboveground residues in each region (mio. tDM)
+ vm_res_biomass_bg(i,kcr,w,dm_cnr)                     production of belowground residues in each region (mio. tDM)
+ vm_res_recycling(i,kcr,w,dm_cnr)                  residues recycled to croplands (mio tons nutrients)
+ vm_res_ag_burn(i,kcr,w,dm_cnr)                    Residues burned on fields in respective attribute units DM GJ Nr P K WM C (mio. tX)
  vm_cost_prod_kres(i,kres)                             Production costs of harvesting crop residues (mio. USD17MER per yr)
 ;
 
 
 *#################### R SECTION START (OUTPUT DECLARATIONS) ####################
 parameters
- ov_res_biomass_ag(t,i,kcr,attributes,type) production of aboveground residues in each region (mio. tDM)
- ov_res_biomass_bg(t,i,kcr,dm_nr,type)      production of belowground residues in each region (mio. tDM)
- ov_res_recycling(t,i,npk,type)             residues recycled to croplands (mio tons nutrients)
- ov_res_ag_burn(t,i,kcr,attributes,type)    Residues burned on fields in respective attribute units DM GJ Nr P K WM C (mio. tX)
- ov_cost_prod_kres(t,i,kres,type)           Production costs of harvesting crop residues (mio. USD17MER per yr)
+ ov_res_biomass_ag(t,i,kcr,w,dm_cnr,type) production of aboveground residues in each region (mio. tDM)
+ ov_res_biomass_bg(t,i,kcr,w,dm_cnr,type) production of belowground residues in each region (mio. tDM)
+ ov_res_recycling(t,i,kcr,w,dm_cnr,type)  residues recycled to croplands (mio tons nutrients)
+ ov_res_ag_burn(t,i,kcr,w,dm_cnr,type)    Residues burned on fields in respective attribute units DM GJ Nr P K WM C (mio. tX)
+ ov_cost_prod_kres(t,i,kres,type)         Production costs of harvesting crop residues (mio. USD17MER per yr)
 ;
 *##################### R SECTION END (OUTPUT DECLARATIONS) #####################
 
diff --git a/modules/18_residues/off/not_used.txt b/modules/18_residues/off/not_used.txt
index 85051d6636..dcaf0f78ad 100644
--- a/modules/18_residues/off/not_used.txt
+++ b/modules/18_residues/off/not_used.txt
@@ -1,6 +1,6 @@
 name,type,reason
+vm_prod_reg,input,questionnaire
 im_development_state,input,questionnaire
 fm_attributes,input,questionnaire
-vm_prod_reg,input,questionnaire
 vm_area,input,questionnaire
-vm_prod,input,questionnaire
\ No newline at end of file
+vm_prod_kcr_w,input,questionnaire
diff --git a/modules/18_residues/off/postsolve.gms b/modules/18_residues/off/postsolve.gms
index bbc140e738..c280cd0977 100644
--- a/modules/18_residues/off/postsolve.gms
+++ b/modules/18_residues/off/postsolve.gms
@@ -6,24 +6,24 @@
 *** |  Contact: magpie@pik-potsdam.de
 
 *#################### R SECTION START (OUTPUT DEFINITIONS) #####################
- ov_res_biomass_ag(t,i,kcr,attributes,"marginal") = vm_res_biomass_ag.m(i,kcr,attributes);
- ov_res_biomass_bg(t,i,kcr,dm_nr,"marginal")      = vm_res_biomass_bg.m(i,kcr,dm_nr);
- ov_res_recycling(t,i,npk,"marginal")             = vm_res_recycling.m(i,npk);
- ov_res_ag_burn(t,i,kcr,attributes,"marginal")    = vm_res_ag_burn.m(i,kcr,attributes);
- ov_cost_prod_kres(t,i,kres,"marginal")           = vm_cost_prod_kres.m(i,kres);
- ov_res_biomass_ag(t,i,kcr,attributes,"level")    = vm_res_biomass_ag.l(i,kcr,attributes);
- ov_res_biomass_bg(t,i,kcr,dm_nr,"level")         = vm_res_biomass_bg.l(i,kcr,dm_nr);
- ov_res_recycling(t,i,npk,"level")                = vm_res_recycling.l(i,npk);
- ov_res_ag_burn(t,i,kcr,attributes,"level")       = vm_res_ag_burn.l(i,kcr,attributes);
- ov_cost_prod_kres(t,i,kres,"level")              = vm_cost_prod_kres.l(i,kres);
- ov_res_biomass_ag(t,i,kcr,attributes,"upper")    = vm_res_biomass_ag.up(i,kcr,attributes);
- ov_res_biomass_bg(t,i,kcr,dm_nr,"upper")         = vm_res_biomass_bg.up(i,kcr,dm_nr);
- ov_res_recycling(t,i,npk,"upper")                = vm_res_recycling.up(i,npk);
- ov_res_ag_burn(t,i,kcr,attributes,"upper")       = vm_res_ag_burn.up(i,kcr,attributes);
- ov_cost_prod_kres(t,i,kres,"upper")              = vm_cost_prod_kres.up(i,kres);
- ov_res_biomass_ag(t,i,kcr,attributes,"lower")    = vm_res_biomass_ag.lo(i,kcr,attributes);
- ov_res_biomass_bg(t,i,kcr,dm_nr,"lower")         = vm_res_biomass_bg.lo(i,kcr,dm_nr);
- ov_res_recycling(t,i,npk,"lower")                = vm_res_recycling.lo(i,npk);
- ov_res_ag_burn(t,i,kcr,attributes,"lower")       = vm_res_ag_burn.lo(i,kcr,attributes);
- ov_cost_prod_kres(t,i,kres,"lower")              = vm_cost_prod_kres.lo(i,kres);
+ ov_res_biomass_ag(t,i,kcr,w,dm_cnr,"marginal") = vm_res_biomass_ag.m(i,kcr,w,dm_cnr);
+ ov_res_biomass_bg(t,i,kcr,w,dm_cnr,"marginal") = vm_res_biomass_bg.m(i,kcr,w,dm_cnr);
+ ov_res_recycling(t,i,kcr,w,dm_cnr,"marginal")  = vm_res_recycling.m(i,kcr,w,dm_cnr);
+ ov_res_ag_burn(t,i,kcr,w,dm_cnr,"marginal")    = vm_res_ag_burn.m(i,kcr,w,dm_cnr);
+ ov_cost_prod_kres(t,i,kres,"marginal")         = vm_cost_prod_kres.m(i,kres);
+ ov_res_biomass_ag(t,i,kcr,w,dm_cnr,"level")    = vm_res_biomass_ag.l(i,kcr,w,dm_cnr);
+ ov_res_biomass_bg(t,i,kcr,w,dm_cnr,"level")    = vm_res_biomass_bg.l(i,kcr,w,dm_cnr);
+ ov_res_recycling(t,i,kcr,w,dm_cnr,"level")     = vm_res_recycling.l(i,kcr,w,dm_cnr);
+ ov_res_ag_burn(t,i,kcr,w,dm_cnr,"level")       = vm_res_ag_burn.l(i,kcr,w,dm_cnr);
+ ov_cost_prod_kres(t,i,kres,"level")            = vm_cost_prod_kres.l(i,kres);
+ ov_res_biomass_ag(t,i,kcr,w,dm_cnr,"upper")    = vm_res_biomass_ag.up(i,kcr,w,dm_cnr);
+ ov_res_biomass_bg(t,i,kcr,w,dm_cnr,"upper")    = vm_res_biomass_bg.up(i,kcr,w,dm_cnr);
+ ov_res_recycling(t,i,kcr,w,dm_cnr,"upper")     = vm_res_recycling.up(i,kcr,w,dm_cnr);
+ ov_res_ag_burn(t,i,kcr,w,dm_cnr,"upper")       = vm_res_ag_burn.up(i,kcr,w,dm_cnr);
+ ov_cost_prod_kres(t,i,kres,"upper")            = vm_cost_prod_kres.up(i,kres);
+ ov_res_biomass_ag(t,i,kcr,w,dm_cnr,"lower")    = vm_res_biomass_ag.lo(i,kcr,w,dm_cnr);
+ ov_res_biomass_bg(t,i,kcr,w,dm_cnr,"lower")    = vm_res_biomass_bg.lo(i,kcr,w,dm_cnr);
+ ov_res_recycling(t,i,kcr,w,dm_cnr,"lower")     = vm_res_recycling.lo(i,kcr,w,dm_cnr);
+ ov_res_ag_burn(t,i,kcr,w,dm_cnr,"lower")       = vm_res_ag_burn.lo(i,kcr,w,dm_cnr);
+ ov_cost_prod_kres(t,i,kres,"lower")            = vm_cost_prod_kres.lo(i,kres);
 *##################### R SECTION END (OUTPUT DEFINITIONS) ######################
diff --git a/modules/18_residues/off/preloop.gms b/modules/18_residues/off/preloop.gms
index 039b71abcd..8bfcfd3205 100644
--- a/modules/18_residues/off/preloop.gms
+++ b/modules/18_residues/off/preloop.gms
@@ -7,8 +7,8 @@
 
 
 
-vm_res_biomass_ag.fx(i,kcr,attributes) = 0;
-vm_res_biomass_bg.fx(i,kcr,dm_nr)      = 0;
-vm_res_recycling.fx(i,npk)             = 0;
-vm_res_ag_burn.fx(i,kcr,attributes)    = 0;
-vm_cost_prod_kres.fx(i,kres)           = 0;
+vm_res_biomass_ag.fx(i,kcr,w,dm_cnr) = 0;
+vm_res_biomass_bg.fx(i,kcr,w,dm_cnr)     = 0;
+vm_res_recycling.fx(i,kcr,w,dm_cnr)  = 0;
+vm_res_ag_burn.fx(i,kcr,w,dm_cnr)    = 0;
+vm_cost_prod_kres.fx(i,kres)             = 0;
diff --git a/modules/18_residues/off/sets.gms b/modules/18_residues/off/sets.gms
index 5ec47281b4..fecc54a446 100644
--- a/modules/18_residues/off/sets.gms
+++ b/modules/18_residues/off/sets.gms
@@ -7,8 +7,8 @@
 
 
 sets
-dm_nr(attributes) dry matter and nr
-/dm, nr/
+dm_cnr(attributes) dry matter and nr
+/dm, nr, c/
 ;
 
 *** EOF sets.gms ***
diff --git a/modules/30_croparea/detail_apr24/declarations.gms b/modules/30_croparea/detail_apr24/declarations.gms
index d60c7a369b..7365f13f6b 100644
--- a/modules/30_croparea/detail_apr24/declarations.gms
+++ b/modules/30_croparea/detail_apr24/declarations.gms
@@ -25,9 +25,11 @@ positive variables
  v30_penalty(j,rota30)                Penalty for violating rotational constraints (mio. USD17MER)
  v30_betr_missing(j)                  Missing bioenergy tree land towards target (mio. ha)
  v30_crop_area(i)                     Total regional crop production area (mio. ha)
+ vm_prod_kcr_w(j,kcr,w)               Agricultural production per crop group and irrigation type (mio. tDM per yr)
 ;
 
 equations
+ q30_prod_kcr_w(j,kcr,w)            Irrigation type specific production of cropped products (mio. tDM per yr)
  q30_prod(j,kcr)                      Production of cropped products (mio. tDM)
  q30_betr_missing(j)                Missing bioenergy tree land towards target (mio. ha)
  q30_rotation_penalty(i)              Total penalty for rotational constraint violations (mio. USD17MER)
@@ -51,6 +53,8 @@ parameters
  ov30_penalty(t,j,rota30,type)               Penalty for violating rotational constraints (mio. USD17MER)
  ov30_betr_missing(t,j,type)                 Missing bioenergy tree land towards target (mio. ha)
  ov30_crop_area(t,i,type)                    Total regional crop production area (mio. ha)
+ ov_prod_kcr_w(t,j,kcr,w,type)               Agricultural production per crop group and irrigation type (mio. tDM per yr)
+ oq30_prod_kcr_w(t,j,kcr,w,type)             Irrigation type specific production of cropped products (mio. tDM per yr)
  oq30_prod(t,j,kcr,type)                     Production of cropped products (mio. tDM)
  oq30_betr_missing(t,j,type)                 Missing bioenergy tree land towards target (mio. ha)
  oq30_rotation_penalty(t,i,type)             Total penalty for rotational constraint violations (mio. USD17MER)
diff --git a/modules/30_croparea/detail_apr24/equations.gms b/modules/30_croparea/detail_apr24/equations.gms
index 2f19a5fcf5..7bf4181c4b 100644
--- a/modules/30_croparea/detail_apr24/equations.gms
+++ b/modules/30_croparea/detail_apr24/equations.gms
@@ -8,11 +8,16 @@
 *' @equations
 
 *' Agricultural production is calculated by multiplying the area under
-*' production with corresponding yields. Production from rainfed and irrigated
-*' areas is summed up:
+*' production with corresponding yields.
 
-  q30_prod(j2,kcr) ..
-    vm_prod(j2,kcr) =e= sum(w, vm_area(j2,kcr,w) * vm_yld(j2,kcr,w));
+ q30_prod_kcr_w(j2,kcr,w) ..
+   vm_prod_kcr_w(j2,kcr,w) =e= vm_area(j2,kcr,w) * vm_yld(j2,kcr,w);
+
+*' For total production rainfed and irrigated production is summed up:
+*** Maybe test here  other types of contrains (lower)
+
+ q30_prod(j2,kcr) ..
+  vm_prod(j2,kcr) =e= sum(w, vm_prod_kcr_w(j2,kcr,w));
 
 *' A penalty is applied for the violation of bioenergy tree (betr) rules.
 *' The penalty applies to the missing bioenergy tree land, i.e. where bioenergy tree land 
diff --git a/modules/30_croparea/detail_apr24/postsolve.gms b/modules/30_croparea/detail_apr24/postsolve.gms
index e97dda0ca3..2613a82124 100644
--- a/modules/30_croparea/detail_apr24/postsolve.gms
+++ b/modules/30_croparea/detail_apr24/postsolve.gms
@@ -14,6 +14,8 @@
  ov30_penalty(t,j,rota30,"marginal")               = v30_penalty.m(j,rota30);
  ov30_betr_missing(t,j,"marginal")                 = v30_betr_missing.m(j);
  ov30_crop_area(t,i,"marginal")                    = v30_crop_area.m(i);
+ ov_prod_kcr_w(t,j,kcr,w,"marginal")               = vm_prod_kcr_w.m(j,kcr,w);
+ oq30_prod_kcr_w(t,j,kcr,w,"marginal")             = q30_prod_kcr_w.m(j,kcr,w);
  oq30_prod(t,j,kcr,"marginal")                     = q30_prod.m(j,kcr);
  oq30_betr_missing(t,j,"marginal")                 = q30_betr_missing.m(j);
  oq30_rotation_penalty(t,i,"marginal")             = q30_rotation_penalty.m(i);
@@ -33,6 +35,8 @@
  ov30_penalty(t,j,rota30,"level")                  = v30_penalty.l(j,rota30);
  ov30_betr_missing(t,j,"level")                    = v30_betr_missing.l(j);
  ov30_crop_area(t,i,"level")                       = v30_crop_area.l(i);
+ ov_prod_kcr_w(t,j,kcr,w,"level")                  = vm_prod_kcr_w.l(j,kcr,w);
+ oq30_prod_kcr_w(t,j,kcr,w,"level")                = q30_prod_kcr_w.l(j,kcr,w);
  oq30_prod(t,j,kcr,"level")                        = q30_prod.l(j,kcr);
  oq30_betr_missing(t,j,"level")                    = q30_betr_missing.l(j);
  oq30_rotation_penalty(t,i,"level")                = q30_rotation_penalty.l(i);
@@ -52,6 +56,8 @@
  ov30_penalty(t,j,rota30,"upper")                  = v30_penalty.up(j,rota30);
  ov30_betr_missing(t,j,"upper")                    = v30_betr_missing.up(j);
  ov30_crop_area(t,i,"upper")                       = v30_crop_area.up(i);
+ ov_prod_kcr_w(t,j,kcr,w,"upper")                  = vm_prod_kcr_w.up(j,kcr,w);
+ oq30_prod_kcr_w(t,j,kcr,w,"upper")                = q30_prod_kcr_w.up(j,kcr,w);
  oq30_prod(t,j,kcr,"upper")                        = q30_prod.up(j,kcr);
  oq30_betr_missing(t,j,"upper")                    = q30_betr_missing.up(j);
  oq30_rotation_penalty(t,i,"upper")                = q30_rotation_penalty.up(i);
@@ -71,6 +77,8 @@
  ov30_penalty(t,j,rota30,"lower")                  = v30_penalty.lo(j,rota30);
  ov30_betr_missing(t,j,"lower")                    = v30_betr_missing.lo(j);
  ov30_crop_area(t,i,"lower")                       = v30_crop_area.lo(i);
+ ov_prod_kcr_w(t,j,kcr,w,"lower")                  = vm_prod_kcr_w.lo(j,kcr,w);
+ oq30_prod_kcr_w(t,j,kcr,w,"lower")                = q30_prod_kcr_w.lo(j,kcr,w);
  oq30_prod(t,j,kcr,"lower")                        = q30_prod.lo(j,kcr);
  oq30_betr_missing(t,j,"lower")                    = q30_betr_missing.lo(j);
  oq30_rotation_penalty(t,i,"lower")                = q30_rotation_penalty.lo(i);
diff --git a/modules/30_croparea/simple_apr24/declarations.gms b/modules/30_croparea/simple_apr24/declarations.gms
index 3430df82f6..b3c1c352e5 100644
--- a/modules/30_croparea/simple_apr24/declarations.gms
+++ b/modules/30_croparea/simple_apr24/declarations.gms
@@ -20,9 +20,11 @@ positive variables
  vm_carbon_stock_croparea(j,ag_pools)   Carbon stock in croparea (tC)
  v30_betr_missing(j)                    Missing bioenergy tree land towards target (mio. ha)
  v30_crop_area(i)                       Total regional crop production area (mio. ha)
+ vm_prod_kcr_w(j,kcr,w)                 Agricultural production per crop group and irrigation type (mio. tDM per yr)
 ;
 
 equations
+ q30_prod_kcr_w(j,kcr,w)            Irrigation type specific production of cropped products (mio. tDM per yr)
  q30_prod(j,kcr)                    Production of cropped products (mio. tDM)
  q30_betr_missing(j)                Missing bioenergy tree land towards target (mio. ha)
  q30_cost(i)                        Cost (mio. USD17MER)
@@ -41,6 +43,8 @@ parameters
  ov_carbon_stock_croparea(t,j,ag_pools,type) Carbon stock in croparea (tC)
  ov30_betr_missing(t,j,type)                 Missing bioenergy tree land towards target (mio. ha)
  ov30_crop_area(t,i,type)                    Total regional crop production area (mio. ha)
+ ov_prod_kcr_w(t,j,kcr,w,type)               Agricultural production per crop group and irrigation type (mio. tDM per yr)
+ oq30_prod_kcr_w(t,j,kcr,w,type)             Irrigation type specific production of cropped products (mio. tDM per yr)
  oq30_prod(t,j,kcr,type)                     Production of cropped products (mio. tDM)
  oq30_betr_missing(t,j,type)                 Missing bioenergy tree land towards target (mio. ha)
  oq30_cost(t,i,type)                         Cost (mio. USD17MER)
diff --git a/modules/30_croparea/simple_apr24/equations.gms b/modules/30_croparea/simple_apr24/equations.gms
index 0c9a633dd8..02062a70f5 100644
--- a/modules/30_croparea/simple_apr24/equations.gms
+++ b/modules/30_croparea/simple_apr24/equations.gms
@@ -8,11 +8,16 @@
 *' @equations
 
 *' Agricultural production is calculated by multiplying the area under
-*' production with corresponding yields. Production from rainfed and irrigated
-*' areas is summed up:
+*' production with corresponding yields.
+
+ q30_prod_kcr_w(j2,kcr,w) ..
+   vm_prod_kcr_w(j2,kcr,w) =e= vm_area(j2,kcr,w) * vm_yld(j2,kcr,w);
+
+*' For total production rainfed and irrigated production is summed up:
+*** Maybe test here  other types of contrains (lower)
 
  q30_prod(j2,kcr) ..
-  vm_prod(j2,kcr) =e= sum(w, vm_area(j2,kcr,w) * vm_yld(j2,kcr,w));
+  vm_prod(j2,kcr) =e= sum(w, vm_prod_kcr_w(j2,kcr,w));
 
 *' A penalty is applied for the violation of bioenergy tree (betr) rules.
 *' The penalty applies to the missing bioenergy tree land, i.e. where bioenergy tree land 
diff --git a/modules/30_croparea/simple_apr24/postsolve.gms b/modules/30_croparea/simple_apr24/postsolve.gms
index b402e3eca0..02daeab516 100644
--- a/modules/30_croparea/simple_apr24/postsolve.gms
+++ b/modules/30_croparea/simple_apr24/postsolve.gms
@@ -12,6 +12,8 @@
  ov_carbon_stock_croparea(t,j,ag_pools,"marginal") = vm_carbon_stock_croparea.m(j,ag_pools);
  ov30_betr_missing(t,j,"marginal")                 = v30_betr_missing.m(j);
  ov30_crop_area(t,i,"marginal")                    = v30_crop_area.m(i);
+ ov_prod_kcr_w(t,j,kcr,w,"marginal")               = vm_prod_kcr_w.m(j,kcr,w);
+ oq30_prod_kcr_w(t,j,kcr,w,"marginal")             = q30_prod_kcr_w.m(j,kcr,w);
  oq30_prod(t,j,kcr,"marginal")                     = q30_prod.m(j,kcr);
  oq30_betr_missing(t,j,"marginal")                 = q30_betr_missing.m(j);
  oq30_cost(t,i,"marginal")                         = q30_cost.m(i);
@@ -26,6 +28,8 @@
  ov_carbon_stock_croparea(t,j,ag_pools,"level")    = vm_carbon_stock_croparea.l(j,ag_pools);
  ov30_betr_missing(t,j,"level")                    = v30_betr_missing.l(j);
  ov30_crop_area(t,i,"level")                       = v30_crop_area.l(i);
+ ov_prod_kcr_w(t,j,kcr,w,"level")                  = vm_prod_kcr_w.l(j,kcr,w);
+ oq30_prod_kcr_w(t,j,kcr,w,"level")                = q30_prod_kcr_w.l(j,kcr,w);
  oq30_prod(t,j,kcr,"level")                        = q30_prod.l(j,kcr);
  oq30_betr_missing(t,j,"level")                    = q30_betr_missing.l(j);
  oq30_cost(t,i,"level")                            = q30_cost.l(i);
@@ -40,6 +44,8 @@
  ov_carbon_stock_croparea(t,j,ag_pools,"upper")    = vm_carbon_stock_croparea.up(j,ag_pools);
  ov30_betr_missing(t,j,"upper")                    = v30_betr_missing.up(j);
  ov30_crop_area(t,i,"upper")                       = v30_crop_area.up(i);
+ ov_prod_kcr_w(t,j,kcr,w,"upper")                  = vm_prod_kcr_w.up(j,kcr,w);
+ oq30_prod_kcr_w(t,j,kcr,w,"upper")                = q30_prod_kcr_w.up(j,kcr,w);
  oq30_prod(t,j,kcr,"upper")                        = q30_prod.up(j,kcr);
  oq30_betr_missing(t,j,"upper")                    = q30_betr_missing.up(j);
  oq30_cost(t,i,"upper")                            = q30_cost.up(i);
@@ -54,6 +60,8 @@
  ov_carbon_stock_croparea(t,j,ag_pools,"lower")    = vm_carbon_stock_croparea.lo(j,ag_pools);
  ov30_betr_missing(t,j,"lower")                    = v30_betr_missing.lo(j);
  ov30_crop_area(t,i,"lower")                       = v30_crop_area.lo(i);
+ ov_prod_kcr_w(t,j,kcr,w,"lower")                  = vm_prod_kcr_w.lo(j,kcr,w);
+ oq30_prod_kcr_w(t,j,kcr,w,"lower")                = q30_prod_kcr_w.lo(j,kcr,w);
  oq30_prod(t,j,kcr,"lower")                        = q30_prod.lo(j,kcr);
  oq30_betr_missing(t,j,"lower")                    = q30_betr_missing.lo(j);
  oq30_cost(t,i,"lower")                            = q30_cost.lo(i);
diff --git a/modules/50_nr_soil_budget/macceff_aug22/equations.gms b/modules/50_nr_soil_budget/macceff_aug22/equations.gms
index b0055f341f..f1f5680774 100644
--- a/modules/50_nr_soil_budget/macceff_aug22/equations.gms
+++ b/modules/50_nr_soil_budget/macceff_aug22/equations.gms
@@ -21,13 +21,13 @@
 
 q50_nr_inputs(i2) ..
                 v50_nr_inputs(i2) =e=
-                vm_res_recycling(i2,"nr")
+                sum((kcr,w), vm_res_recycling(i2,kcr,w,"nr"))
                   + sum((cell(i2,j2),kcr,w), vm_area(j2,kcr,w) * f50_nr_fix_area(kcr))
                   + sum(cell(i2,j2),vm_fallow(j2) * f50_nr_fix_area("tece"))
                   + vm_manure_recycling(i2,"nr")
                   + sum(kli, vm_manure(i2, kli, "stubble_grazing","nr"))
                   + vm_nr_inorg_fert_reg(i2,"crop")
-                  + sum(cell(i2,j2),vm_nr_som_fertilizer(j2))
+                  + vm_nr_som_fertilizer(i2)
                   + sum(ct,f50_nitrogen_balanceflow(ct,i2))
                   + v50_nr_deposition(i2,"crop");
 
@@ -37,8 +37,8 @@ q50_nr_inputs(i2) ..
                  v50_nr_withdrawals(i2,kcr) =e=
                  (1-sum(ct,f50_nr_fix_ndfa(ct,i2,kcr))) *
                  (vm_prod_reg(i2,kcr) * fm_attributes("nr",kcr)
-                    + vm_res_biomass_ag(i2,kcr,"nr")
-                    + vm_res_biomass_bg(i2,kcr,"nr"))
+                    + sum(w, vm_res_biomass_ag(i2,kcr,w,"nr")
+                           + vm_res_biomass_bg(i2,kcr,w,"nr")))
                  - vm_dem_seed(i2,kcr)  * fm_attributes("nr",kcr)
                  ;
 
diff --git a/modules/51_nitrogen/rescaled_jan21/equations.gms b/modules/51_nitrogen/rescaled_jan21/equations.gms
index 2f04b0902d..c4e7245e1b 100644
--- a/modules/51_nitrogen/rescaled_jan21/equations.gms
+++ b/modules/51_nitrogen/rescaled_jan21/equations.gms
@@ -42,20 +42,20 @@
  q51_emissions_resid(i2,n_pollutants_direct)..
                  vm_emissions_reg(i2,"resid",n_pollutants_direct)
                  =e=
-                 vm_res_recycling(i2,"nr") * sum(ct, i51_ef_n_soil(ct,i2,n_pollutants_direct,"resid"))
+                 sum((kcr,w), vm_res_recycling(i2,kcr,w,"nr")) * sum(ct, i51_ef_n_soil(ct,i2,n_pollutants_direct,"resid"))
                  / (1-s51_snupe_base) * (1-vm_nr_eff(i2));
 
 *' emissions from burning crop residues, N2O and NOx
  q51_emissions_resid_burn(i2,n_pollutants_direct)..
                  vm_emissions_reg(i2,"resid_burn",n_pollutants_direct)
                  =e=
-                 sum(kcr, vm_res_ag_burn(i2,kcr,"dm")) * f51_ef_resid_burn(n_pollutants_direct);
+                 sum((kcr,w), vm_res_ag_burn(i2,kcr,w,"dm")) * f51_ef_resid_burn(n_pollutants_direct);
 
 *' soil organic matter loss:
  q51_emissions_som(i2,n_pollutants_direct)..
                  vm_emissions_reg(i2,"som",n_pollutants_direct)
                  =e=
-                 sum(cell(i2,j2),vm_nr_som(j2)) * sum(ct, i51_ef_n_soil(ct,i2,n_pollutants_direct,"som"))
+                 vm_nr_som(i2) * sum(ct, i51_ef_n_soil(ct,i2,n_pollutants_direct,"som"))
                  / (1-s51_snupe_base) * (1-vm_nr_eff(i2));
 
 *' animal waste management
diff --git a/modules/53_methane/ipcc2006_aug22/equations.gms b/modules/53_methane/ipcc2006_aug22/equations.gms
index 43c572e114..04ba5913bb 100644
--- a/modules/53_methane/ipcc2006_aug22/equations.gms
+++ b/modules/53_methane/ipcc2006_aug22/equations.gms
@@ -69,4 +69,4 @@
 
  q53_emissions_resid_burn(i2) ..
     vm_emissions_reg(i2,"resid_burn","ch4") =e=
-      sum(kcr, vm_res_ag_burn(i2,kcr,"dm")) * s53_ef_ch4_res_ag_burn;
+      sum((kcr,w), vm_res_ag_burn(i2,kcr,w,"dm")) * s53_ef_ch4_res_ag_burn;
diff --git a/modules/56_ghg_policy/price_aug22/input.gms b/modules/56_ghg_policy/price_aug22/input.gms
index 164f887f84..e57b0a549e 100644
--- a/modules/56_ghg_policy/price_aug22/input.gms
+++ b/modules/56_ghg_policy/price_aug22/input.gms
@@ -58,7 +58,6 @@ sets
 
 pollutants_fader(pollutants) pollutants affected by GHG policy fader 
               / co2_c, ch4, n2o_n_direct, n2o_n_indirect, nh3_n, no2_n, no3_n /
-
 ;
 
 scalars
diff --git a/modules/59_som/cellpool_jan23/declarations.gms b/modules/59_som/cellpool_jan23/declarations.gms
index fd21f13631..e724c5d907 100644
--- a/modules/59_som/cellpool_jan23/declarations.gms
+++ b/modules/59_som/cellpool_jan23/declarations.gms
@@ -28,9 +28,9 @@ equations
          q59_som_target_cropland(j)                       Estimates the long-term target state of cropland (mio. tC)
          q59_som_target_noncropland(j,noncropland59)      Estimates the long-term target state of noncropland (mio. tC)
          q59_som_pool(j,land)                             Actual C pool (mio. tC)
-         q59_nr_som(j)                                    Soil organic matter loss (Mt N per yr)
-         q59_nr_som_fertilizer(j)                         Bound of nitrogen fertilizer of soil organic matter loss (Mt N per yr)
-         q59_nr_som_fertilizer2(j)                        Fraction of soil organic matter loss take is taken up by plants (Mt N per yr)
+         q59_nr_som(i)                                    Soil organic matter loss (Mt N per yr)
+         q59_nr_som_fertilizer(i)                         Bound of nitrogen fertilizer of soil organic matter loss (Mt N per yr)
+         q59_nr_som_fertilizer2(i)                        Fraction of soil organic matter loss take is taken up by plants (Mt N per yr)
          q59_carbon_soil(j,land,stockType)                Soil carbon content calculation (mio. tC)
          q59_cost_scm(j)                                  Recurring cost for soil carbon management on cropland (mio. USD17MER per yr)       
 ;
@@ -42,8 +42,8 @@ positive variables
 ;
 
 variables
-         vm_nr_som(j)                                       Release of soil organic matter (Mt N per yr)
-         vm_nr_som_fertilizer(j)                            Uptake of soil organic matter from plants (Mt N per yr)
+         vm_nr_som(i)                                       Release of soil organic matter (Mt N per yr)
+         vm_nr_som_fertilizer(i)                            Uptake of soil organic matter from plants (Mt N per yr)
 ;
 
 *#################### R SECTION START (OUTPUT DECLARATIONS) ####################
@@ -51,14 +51,14 @@ parameters
  ov59_som_target(t,j,land,type)                      Long-term target state of C pool (mio. tC)
  ov59_som_pool(t,j,land,type)                        Soil organic matter pool (mio. tC)
  ov_cost_scm(t,j,type)                               Recurring cost for soil carbon management on cropland (mio. USD17MER per yr)
- ov_nr_som(t,j,type)                                 Release of soil organic matter (Mt N per yr)
- ov_nr_som_fertilizer(t,j,type)                      Uptake of soil organic matter from plants (Mt N per yr)
+ ov_nr_som(t,i,type)                                 Release of soil organic matter (Mt N per yr)
+ ov_nr_som_fertilizer(t,i,type)                      Uptake of soil organic matter from plants (Mt N per yr)
  oq59_som_target_cropland(t,j,type)                  Estimates the long-term target state of cropland (mio. tC)
  oq59_som_target_noncropland(t,j,noncropland59,type) Estimates the long-term target state of noncropland (mio. tC)
  oq59_som_pool(t,j,land,type)                        Actual C pool (mio. tC)
- oq59_nr_som(t,j,type)                               Soil organic matter loss (Mt N per yr)
- oq59_nr_som_fertilizer(t,j,type)                    Bound of nitrogen fertilizer of soil organic matter loss (Mt N per yr)
- oq59_nr_som_fertilizer2(t,j,type)                   Fraction of soil organic matter loss take is taken up by plants (Mt N per yr)
+ oq59_nr_som(t,i,type)                               Soil organic matter loss (Mt N per yr)
+ oq59_nr_som_fertilizer(t,i,type)                    Bound of nitrogen fertilizer of soil organic matter loss (Mt N per yr)
+ oq59_nr_som_fertilizer2(t,i,type)                   Fraction of soil organic matter loss take is taken up by plants (Mt N per yr)
  oq59_carbon_soil(t,j,land,stockType,type)           Soil carbon content calculation (mio. tC)
  oq59_cost_scm(t,j,type)                             Recurring cost for soil carbon management on cropland (mio. USD17MER per yr)
 ;
diff --git a/modules/59_som/cellpool_jan23/equations.gms b/modules/59_som/cellpool_jan23/equations.gms
index f9de344608..341c6ae543 100644
--- a/modules/59_som/cellpool_jan23/equations.gms
+++ b/modules/59_som/cellpool_jan23/equations.gms
@@ -66,37 +66,34 @@ q59_carbon_soil(j2,land,stockType) ..
 *' The annual nitrogen release (or sink) for cropland soils is than
 *' calculated by the loss of soil organic carbon given by
 
-q59_nr_som(j2) ..
-           vm_nr_som(j2)
-           =e= sum(ct,i59_lossrate(ct))/m_timestep_length*1/15
-               * (sum((ct,land_from), p59_carbon_density(ct,j2,land_from) *
-                   vm_lu_transitions(j2,land_from,"crop"))
-               - v59_som_target(j2,"crop"))
+q59_nr_som(i2) ..
+           vm_nr_som(i2)
+           =e= sum(ct, i59_lossrate(ct)) / m_timestep_length * 1/15 *
+               sum(cell(i2, j2), sum((ct, land_from), p59_carbon_density(ct, j2, land_from) *
+                   vm_lu_transitions(j2, land_from, "crop")) - v59_som_target(j2, "crop"))
            ;
 *' with the carbon to nitrogen ratio of soils assumed to be 15:1.
 
 *' The amount of nitrogen that becomes available to cropland farming is
 *' limited by loss of soil organic matter by
 
-q59_nr_som_fertilizer(j2) ..
-          vm_nr_som_fertilizer(j2)
+q59_nr_som_fertilizer(i2) ..
+          vm_nr_som_fertilizer(i2)
           =l=
-          vm_nr_som(j2);
+          vm_nr_som(i2);
 
 *' as well as by the amount that crops can take up
 
-q59_nr_som_fertilizer2(j2) ..
-          vm_nr_som_fertilizer(j2)
+q59_nr_som_fertilizer2(i2) ..
+          vm_nr_som_fertilizer(i2)
           =l=
-          vm_landexpansion(j2,"crop") * s59_nitrogen_uptake;
+          sum(cell(i2, j2), vm_landexpansion(j2, "crop")) * s59_nitrogen_uptake;
 
 *' Here we assume a maximum of 200 kg on the expanded area.
 
-
 *' Cost for soil carbon management are based on a per hectare value
 
   q59_cost_scm(j2) ..
     vm_cost_scm(j2) =e= 
       sum((kcr,w), vm_area(j2,kcr,w)) *
        sum(ct, i59_scm_target(ct,j2)) * s59_cost_scm_recur;
-
diff --git a/modules/59_som/cellpool_jan23/not_used.txt b/modules/59_som/cellpool_jan23/not_used.txt
index a62a4ec738..51ff495d51 100644
--- a/modules/59_som/cellpool_jan23/not_used.txt
+++ b/modules/59_som/cellpool_jan23/not_used.txt
@@ -1,2 +1,3 @@
 name,type,reason
+vm_res_recycling,input,questionnaire
 vm_land_other,input,not needed
diff --git a/modules/59_som/cellpool_jan23/postsolve.gms b/modules/59_som/cellpool_jan23/postsolve.gms
index ea42e490a4..0cb2b6e5ca 100644
--- a/modules/59_som/cellpool_jan23/postsolve.gms
+++ b/modules/59_som/cellpool_jan23/postsolve.gms
@@ -13,53 +13,53 @@ pc59_carbon_density(j,land)$(pc59_land_before(j,land) > 1e-10) = pc59_som_pool(j
  ov59_som_target(t,j,land,"marginal")                      = v59_som_target.m(j,land);
  ov59_som_pool(t,j,land,"marginal")                        = v59_som_pool.m(j,land);
  ov_cost_scm(t,j,"marginal")                               = vm_cost_scm.m(j);
- ov_nr_som(t,j,"marginal")                                 = vm_nr_som.m(j);
- ov_nr_som_fertilizer(t,j,"marginal")                      = vm_nr_som_fertilizer.m(j);
+ ov_nr_som(t,i,"marginal")                                 = vm_nr_som.m(i);
+ ov_nr_som_fertilizer(t,i,"marginal")                      = vm_nr_som_fertilizer.m(i);
  oq59_som_target_cropland(t,j,"marginal")                  = q59_som_target_cropland.m(j);
  oq59_som_target_noncropland(t,j,noncropland59,"marginal") = q59_som_target_noncropland.m(j,noncropland59);
  oq59_som_pool(t,j,land,"marginal")                        = q59_som_pool.m(j,land);
- oq59_nr_som(t,j,"marginal")                               = q59_nr_som.m(j);
- oq59_nr_som_fertilizer(t,j,"marginal")                    = q59_nr_som_fertilizer.m(j);
- oq59_nr_som_fertilizer2(t,j,"marginal")                   = q59_nr_som_fertilizer2.m(j);
+ oq59_nr_som(t,i,"marginal")                               = q59_nr_som.m(i);
+ oq59_nr_som_fertilizer(t,i,"marginal")                    = q59_nr_som_fertilizer.m(i);
+ oq59_nr_som_fertilizer2(t,i,"marginal")                   = q59_nr_som_fertilizer2.m(i);
  oq59_carbon_soil(t,j,land,stockType,"marginal")           = q59_carbon_soil.m(j,land,stockType);
  oq59_cost_scm(t,j,"marginal")                             = q59_cost_scm.m(j);
  ov59_som_target(t,j,land,"level")                         = v59_som_target.l(j,land);
  ov59_som_pool(t,j,land,"level")                           = v59_som_pool.l(j,land);
  ov_cost_scm(t,j,"level")                                  = vm_cost_scm.l(j);
- ov_nr_som(t,j,"level")                                    = vm_nr_som.l(j);
- ov_nr_som_fertilizer(t,j,"level")                         = vm_nr_som_fertilizer.l(j);
+ ov_nr_som(t,i,"level")                                    = vm_nr_som.l(i);
+ ov_nr_som_fertilizer(t,i,"level")                         = vm_nr_som_fertilizer.l(i);
  oq59_som_target_cropland(t,j,"level")                     = q59_som_target_cropland.l(j);
  oq59_som_target_noncropland(t,j,noncropland59,"level")    = q59_som_target_noncropland.l(j,noncropland59);
  oq59_som_pool(t,j,land,"level")                           = q59_som_pool.l(j,land);
- oq59_nr_som(t,j,"level")                                  = q59_nr_som.l(j);
- oq59_nr_som_fertilizer(t,j,"level")                       = q59_nr_som_fertilizer.l(j);
- oq59_nr_som_fertilizer2(t,j,"level")                      = q59_nr_som_fertilizer2.l(j);
+ oq59_nr_som(t,i,"level")                                  = q59_nr_som.l(i);
+ oq59_nr_som_fertilizer(t,i,"level")                       = q59_nr_som_fertilizer.l(i);
+ oq59_nr_som_fertilizer2(t,i,"level")                      = q59_nr_som_fertilizer2.l(i);
  oq59_carbon_soil(t,j,land,stockType,"level")              = q59_carbon_soil.l(j,land,stockType);
  oq59_cost_scm(t,j,"level")                                = q59_cost_scm.l(j);
  ov59_som_target(t,j,land,"upper")                         = v59_som_target.up(j,land);
  ov59_som_pool(t,j,land,"upper")                           = v59_som_pool.up(j,land);
  ov_cost_scm(t,j,"upper")                                  = vm_cost_scm.up(j);
- ov_nr_som(t,j,"upper")                                    = vm_nr_som.up(j);
- ov_nr_som_fertilizer(t,j,"upper")                         = vm_nr_som_fertilizer.up(j);
+ ov_nr_som(t,i,"upper")                                    = vm_nr_som.up(i);
+ ov_nr_som_fertilizer(t,i,"upper")                         = vm_nr_som_fertilizer.up(i);
  oq59_som_target_cropland(t,j,"upper")                     = q59_som_target_cropland.up(j);
  oq59_som_target_noncropland(t,j,noncropland59,"upper")    = q59_som_target_noncropland.up(j,noncropland59);
  oq59_som_pool(t,j,land,"upper")                           = q59_som_pool.up(j,land);
- oq59_nr_som(t,j,"upper")                                  = q59_nr_som.up(j);
- oq59_nr_som_fertilizer(t,j,"upper")                       = q59_nr_som_fertilizer.up(j);
- oq59_nr_som_fertilizer2(t,j,"upper")                      = q59_nr_som_fertilizer2.up(j);
+ oq59_nr_som(t,i,"upper")                                  = q59_nr_som.up(i);
+ oq59_nr_som_fertilizer(t,i,"upper")                       = q59_nr_som_fertilizer.up(i);
+ oq59_nr_som_fertilizer2(t,i,"upper")                      = q59_nr_som_fertilizer2.up(i);
  oq59_carbon_soil(t,j,land,stockType,"upper")              = q59_carbon_soil.up(j,land,stockType);
  oq59_cost_scm(t,j,"upper")                                = q59_cost_scm.up(j);
  ov59_som_target(t,j,land,"lower")                         = v59_som_target.lo(j,land);
  ov59_som_pool(t,j,land,"lower")                           = v59_som_pool.lo(j,land);
  ov_cost_scm(t,j,"lower")                                  = vm_cost_scm.lo(j);
- ov_nr_som(t,j,"lower")                                    = vm_nr_som.lo(j);
- ov_nr_som_fertilizer(t,j,"lower")                         = vm_nr_som_fertilizer.lo(j);
+ ov_nr_som(t,i,"lower")                                    = vm_nr_som.lo(i);
+ ov_nr_som_fertilizer(t,i,"lower")                         = vm_nr_som_fertilizer.lo(i);
  oq59_som_target_cropland(t,j,"lower")                     = q59_som_target_cropland.lo(j);
  oq59_som_target_noncropland(t,j,noncropland59,"lower")    = q59_som_target_noncropland.lo(j,noncropland59);
  oq59_som_pool(t,j,land,"lower")                           = q59_som_pool.lo(j,land);
- oq59_nr_som(t,j,"lower")                                  = q59_nr_som.lo(j);
- oq59_nr_som_fertilizer(t,j,"lower")                       = q59_nr_som_fertilizer.lo(j);
- oq59_nr_som_fertilizer2(t,j,"lower")                      = q59_nr_som_fertilizer2.lo(j);
+ oq59_nr_som(t,i,"lower")                                  = q59_nr_som.lo(i);
+ oq59_nr_som_fertilizer(t,i,"lower")                       = q59_nr_som_fertilizer.lo(i);
+ oq59_nr_som_fertilizer2(t,i,"lower")                      = q59_nr_som_fertilizer2.lo(i);
  oq59_carbon_soil(t,j,land,stockType,"lower")              = q59_carbon_soil.lo(j,land,stockType);
  oq59_cost_scm(t,j,"lower")                                = q59_cost_scm.lo(j);
 *##################### R SECTION END (OUTPUT DEFINITIONS) ######################
diff --git a/modules/59_som/module.gms b/modules/59_som/module.gms
index d73e072cfc..5566dda3f2 100644
--- a/modules/59_som/module.gms
+++ b/modules/59_som/module.gms
@@ -19,4 +19,5 @@
 *###################### R SECTION START (MODULETYPES) ##########################
 $Ifi "%som%" == "cellpool_jan23" $include "./modules/59_som/cellpool_jan23/realization.gms"
 $Ifi "%som%" == "static_jan19" $include "./modules/59_som/static_jan19/realization.gms"
+$Ifi "%som%" == "threepool_may23" $include "./modules/59_som/threepool_may23/realization.gms"
 *###################### R SECTION END (MODULETYPES) ############################
diff --git a/modules/59_som/static_jan19/declarations.gms b/modules/59_som/static_jan19/declarations.gms
index 5d83f75915..27ea68eb42 100644
--- a/modules/59_som/static_jan19/declarations.gms
+++ b/modules/59_som/static_jan19/declarations.gms
@@ -12,10 +12,9 @@ parameters
 ;
 
 variables
-        vm_nr_som(j)                        Release of soil organic matter (Mt N per yr)
-        vm_nr_som_fertilizer(j)             Uptake of soil organic matter from plants (Mt N per yr)
+        vm_nr_som(i)                        Release of soil organic matter (Mt N per yr)
+        vm_nr_som_fertilizer(i)             Uptake of soil organic matter from plants (Mt N per yr)
         vm_cost_scm(j)                      Recurring cost for soil carbon management on cropland (mio. USD17MER per yr)
-
 ;
 
 equations
@@ -26,8 +25,8 @@ equations
 
 *#################### R SECTION START (OUTPUT DECLARATIONS) ####################
 parameters
- ov_nr_som(t,j,type)                                       Release of soil organic matter (Mt N per yr)
- ov_nr_som_fertilizer(t,j,type)                            Uptake of soil organic matter from plants (Mt N per yr)
+ ov_nr_som(t,i,type)                                       Release of soil organic matter (Mt N per yr)
+ ov_nr_som_fertilizer(t,i,type)                            Uptake of soil organic matter from plants (Mt N per yr)
  ov_cost_scm(t,j,type)                                     Recurring cost for soil carbon management on cropland (mio. USD17MER per yr)
  oq59_soilcarbon_cropland(t,j,stockType,type)              Cropland soil carbon content calculation (mio. tC)
  oq59_soilcarbon_regular(t,j,regularland59,stockType,type) Regular soil carbon content calculation (mio. tC)
diff --git a/modules/59_som/static_jan19/not_used.txt b/modules/59_som/static_jan19/not_used.txt
index c99b479c30..2339fceb81 100644
--- a/modules/59_som/static_jan19/not_used.txt
+++ b/modules/59_som/static_jan19/not_used.txt
@@ -5,3 +5,4 @@ pm_avl_cropland_iso,input,questionnaire
 vm_landexpansion,input,questionnaire
 vm_lu_transitions,input,questionnaire
 pm_climate_class,input,questionnaire
+vm_res_recycling,input,questionnaire
diff --git a/modules/59_som/static_jan19/postsolve.gms b/modules/59_som/static_jan19/postsolve.gms
index 32fda876c4..c31e2c31d7 100644
--- a/modules/59_som/static_jan19/postsolve.gms
+++ b/modules/59_som/static_jan19/postsolve.gms
@@ -8,26 +8,26 @@
 
 
 *#################### R SECTION START (OUTPUT DEFINITIONS) #####################
- ov_nr_som(t,j,"marginal")                                       = vm_nr_som.m(j);
- ov_nr_som_fertilizer(t,j,"marginal")                            = vm_nr_som_fertilizer.m(j);
+ ov_nr_som(t,i,"marginal")                                       = vm_nr_som.m(i);
+ ov_nr_som_fertilizer(t,i,"marginal")                            = vm_nr_som_fertilizer.m(i);
  ov_cost_scm(t,j,"marginal")                                     = vm_cost_scm.m(j);
  oq59_soilcarbon_cropland(t,j,stockType,"marginal")              = q59_soilcarbon_cropland.m(j,stockType);
  oq59_soilcarbon_regular(t,j,regularland59,stockType,"marginal") = q59_soilcarbon_regular.m(j,regularland59,stockType);
  oq59_soilcarbon_other(t,j,stockType,"marginal")                 = q59_soilcarbon_other.m(j,stockType);
- ov_nr_som(t,j,"level")                                          = vm_nr_som.l(j);
- ov_nr_som_fertilizer(t,j,"level")                               = vm_nr_som_fertilizer.l(j);
+ ov_nr_som(t,i,"level")                                          = vm_nr_som.l(i);
+ ov_nr_som_fertilizer(t,i,"level")                               = vm_nr_som_fertilizer.l(i);
  ov_cost_scm(t,j,"level")                                        = vm_cost_scm.l(j);
  oq59_soilcarbon_cropland(t,j,stockType,"level")                 = q59_soilcarbon_cropland.l(j,stockType);
  oq59_soilcarbon_regular(t,j,regularland59,stockType,"level")    = q59_soilcarbon_regular.l(j,regularland59,stockType);
  oq59_soilcarbon_other(t,j,stockType,"level")                    = q59_soilcarbon_other.l(j,stockType);
- ov_nr_som(t,j,"upper")                                          = vm_nr_som.up(j);
- ov_nr_som_fertilizer(t,j,"upper")                               = vm_nr_som_fertilizer.up(j);
+ ov_nr_som(t,i,"upper")                                          = vm_nr_som.up(i);
+ ov_nr_som_fertilizer(t,i,"upper")                               = vm_nr_som_fertilizer.up(i);
  ov_cost_scm(t,j,"upper")                                        = vm_cost_scm.up(j);
  oq59_soilcarbon_cropland(t,j,stockType,"upper")                 = q59_soilcarbon_cropland.up(j,stockType);
  oq59_soilcarbon_regular(t,j,regularland59,stockType,"upper")    = q59_soilcarbon_regular.up(j,regularland59,stockType);
  oq59_soilcarbon_other(t,j,stockType,"upper")                    = q59_soilcarbon_other.up(j,stockType);
- ov_nr_som(t,j,"lower")                                          = vm_nr_som.lo(j);
- ov_nr_som_fertilizer(t,j,"lower")                               = vm_nr_som_fertilizer.lo(j);
+ ov_nr_som(t,i,"lower")                                          = vm_nr_som.lo(i);
+ ov_nr_som_fertilizer(t,i,"lower")                               = vm_nr_som_fertilizer.lo(i);
  ov_cost_scm(t,j,"lower")                                        = vm_cost_scm.lo(j);
  oq59_soilcarbon_cropland(t,j,stockType,"lower")                 = q59_soilcarbon_cropland.lo(j,stockType);
  oq59_soilcarbon_regular(t,j,regularland59,stockType,"lower")    = q59_soilcarbon_regular.lo(j,regularland59,stockType);
diff --git a/modules/59_som/static_jan19/presolve.gms b/modules/59_som/static_jan19/presolve.gms
index d6dc9d883d..a77f489790 100644
--- a/modules/59_som/static_jan19/presolve.gms
+++ b/modules/59_som/static_jan19/presolve.gms
@@ -5,14 +5,13 @@
 *** |  MAgPIE License Exception, version 1.0 (see LICENSE file).
 *** |  Contact: magpie@pik-potsdam.de
 
-vm_nr_som.fx(j) = 0;
-vm_nr_som_fertilizer.fx(j) = 0;
+vm_nr_som.fx(i) = 0;
+vm_nr_som_fertilizer.fx(i) = 0;
 
 i59_nr_som_exogenous_per_ha(t,i) = 0;
 $if "%c59_exo_scen%" == "constant" i59_nr_som_exogenous_per_ha(t,i)$(sum(cell(i,j),pcm_land(j,"crop")) > 0) = f59_som_exogenous(t,i,"constant")/sum(cell(i,j),pcm_land(j,"crop"));
 $if "%c59_exo_scen%" == "fadeout_2050" i59_nr_som_exogenous_per_ha(t,i)$(sum(cell(i,j),pcm_land(j,"crop")) > 0) = f59_som_exogenous(t,i,"fadeout_2050")/sum(cell(i,j),pcm_land(j,"crop"));
 
-vm_nr_som.fx(j) = sum(cell(i,j),i59_nr_som_exogenous_per_ha(t,i)*pcm_land(j,"crop"));
-vm_nr_som_fertilizer.fx(j) = sum(cell(i,j),i59_nr_som_exogenous_per_ha(t,i)*pcm_land(j,"crop"));
-
+vm_nr_som.fx(i) = i59_nr_som_exogenous_per_ha(t, i) * sum(cell(i,j), pcm_land(j, "crop"));
+vm_nr_som_fertilizer.fx(i) = i59_nr_som_exogenous_per_ha(t, i) * sum(cell(i,j), pcm_land(j, "crop"));
 vm_cost_scm.fx(j) = 0;
diff --git a/modules/59_som/threepool_cell_apr25/declarations.gms b/modules/59_som/threepool_cell_apr25/declarations.gms
new file mode 100644
index 0000000000..783934e056
--- /dev/null
+++ b/modules/59_som/threepool_cell_apr25/declarations.gms
@@ -0,0 +1,74 @@
+*** |  (C) 2008-2023 Potsdam Institute for Climate Impact Research (PIK)
+*** |  authors, and contributors see CITATION.cff file. This file is part
+*** |  of MAgPIE and licensed under AGPL-3.0-or-later. Under Section 7 of
+*** |  AGPL-3.0, you are granted additional permissions described in the
+*** |  MAgPIE License Exception, version 1.0 (see LICENSE file).
+*** |  Contact: magpie@pik-potsdam.de
+
+parameters
+          i59_cinput_multiplier_residue(j, sPools59, kcr)                 Carbon input to soil pool input multipliers (1)
+          i59_topsoilc_decay_max1(t, j, sPools59, w, tillage59)           Soil decay rates for all SOC sub-pools per year cut at 1 (1)
+          pc59_topsoilc_decay_timestep(j, sPools59, w, tillage59)         Soil decay rates for all SOC sub-pools per time steps length (1)
+          p59_topsoilc_density_pre(t_all, j, land, sPools59)              Soil carbon density of the upper layer per hectare before solve (tC per ha)
+          p59_topsoilc_density_post(t_all, j, land, sPools59)             Soil carbon density of the upper layer per hectare after solve (tC per ha)
+          p59_topsoilc_actualstate(j, land, sPools59)                     Actual soil carbon stock per land type (mio. tC)
+          p59_topsoilc_naturalstate(t_all, j, land, sPools59)             Natural soil carbon stock per land type (mio. tC)
+          pc59_topsoilc_natural_steadystate(j, land, sPools59)            Natural steady state soil carbon stpock (mio. tC)
+          pc59_topsoilc_naturalstate_previous(j, land, sPools59)          Natural state of the time step before (mio. tC)
+          i59_subsoilc_density(t_all,j)                                   Subsoil carbon density of per hectare (tC per ha)
+          p59_land_before(j,land)                                         Land area in previous time step (mio. ha)
+;
+
+equations
+         q59_steadystate_term_crop(j, sPools59, w, tillage59)                    Steady-state for SOC stock on cropland (mio. tC)
+         q59_previousstate_term_crop(j, sPools59, w, tillage59)               bla
+         q59_lutransitions_to_cropareas(j, noncropland59)                    bla
+         q59_actualstate_crop(j, sPools59)                                   bla
+         q59_steadystate_term_noncrop(j, noncropland59, sPools59)            bla
+         q59_previousstate_term_noncrop(j, noncropland59, sPools59)             Steady-state for SOC on various non-cropland types (mio. tC)
+         q59_actualstate_noncrop(j, noncropland59, sPools59)                 bla
+         q59_carbon_soil(j, land, stockType)                                 bla
+         q59_nr_som(i)                                                          bla
+         q59_nr_som_fertilizer2(i)                                              bla
+         q59_nr_som_fertilizer(i)                                               bla
+;
+
+positive variables
+         v59_topsoilc_crop_steadystate(j, sPools59, w, tillage59)             bla
+         v59_topsoilc_noncrop_steadystate(j, noncropland59, sPools59)        bla
+         v59_topsoilc_crop_previousstate(j, sPools59, w, tillage59)           bla
+         v59_cropland_transitions(j, tillage59, w, noncropland59)            bla
+         v59_topsoilc_noncrop_previousstate(j, noncropland59, sPools59)      bla
+         v59_topsoilc_actualstate(j, land, sPools59)                         bla
+        vm_cost_scm(j)                      Recurring cost for soil carbon management on cropland (mio. USD17MER per yr)
+;
+
+variables
+         vm_nr_som(i)                                       Release of soil organic matter (Mt N per yr)
+         vm_nr_som_fertilizer(i)                            Uptake of soil organic matter from plants (Mt N per yr)
+;
+
+*#################### R SECTION START (OUTPUT DECLARATIONS) ####################
+parameters
+ ov59_topsoilc_crop_steadystate(t,i,sPools59,w,tillage59,type)        bla
+ ov59_topsoilc_noncrop_steadystate(t,i,noncropland59,sPools59,type)   bla
+ ov59_topsoilc_crop_previousstate(t,i,sPools59,w,tillage59,type)      bla
+ ov59_cropland_transitions(t,i,tillage59,w,noncropland59,type)        bla
+ ov59_topsoilc_noncrop_previousstate(t,i,noncropland59,sPools59,type) bla
+ ov59_topsoilc_actualstate(t,i,land,sPools59,type)                    bla
+ ov_cost_scm(t,j,type)                                                Recurring cost for soil carbon management on cropland (mio. USD17MER per yr)
+ ov_nr_som(t,i,type)                                                  Release of soil organic matter (Mt N per yr)
+ ov_nr_som_fertilizer(t,i,type)                                       Uptake of soil organic matter from plants (Mt N per yr)
+ oq59_steadystate_term_crop(t,i,sPools59,w,tillage59,type)            Steady-state for SOC stock on cropland (mio. tC)
+ oq59_previousstate_term_crop(t,i,sPools59,w,tillage59,type)          bla
+ oq59_lutransitions_to_cropareas(t,i,noncropland59,type)              bla
+ oq59_actualstate_crop(t,i,sPools59,type)                             bla
+ oq59_steadystate_term_noncrop(t,i,noncropland59,sPools59,type)       bla
+ oq59_previousstate_term_noncrop(t,i,noncropland59,sPools59,type)     Steady-state for SOC on various non-cropland types (mio. tC)
+ oq59_actualstate_noncrop(t,i,noncropland59,sPools59,type)            bla
+ oq59_carbon_soil(t,i,land,stockType,type)                            bla
+ oq59_nr_som(t,i,type)                                                bla
+ oq59_nr_som_fertilizer2(t,i,type)                                    bla
+ oq59_nr_som_fertilizer(t,i,type)                                     bla
+;
+*##################### R SECTION END (OUTPUT DECLARATIONS) #####################
diff --git a/modules/59_som/threepool_cell_apr25/equations.gms b/modules/59_som/threepool_cell_apr25/equations.gms
new file mode 100644
index 0000000000..97615da8f8
--- /dev/null
+++ b/modules/59_som/threepool_cell_apr25/equations.gms
@@ -0,0 +1,120 @@
+*** |  (C) 2008-2023 Potsdam Institute for Climate Impact Research (PIK)
+*** |  authors, and contributors see CITATION.cff file. This file is part
+*** |  of MAgPIE and licensed under AGPL-3.0-or-later. Under Section 7 of
+*** |  AGPL-3.0, you are granted additional permissions described in the
+*** |  MAgPIE License Exception, version 1.0 (see LICENSE file).
+*** |  Contact: magpie@pik-potsdam.de
+
+
+*' @equations
+
+*' For every cell a new equilibrium value for the soil organic carbon pool
+*' on cropland is calculated as the sum over all crop types and irrigation regimes via
+
+q59_steadystate_term_crop(j2, sPools59, w, tillage59) .. 
+  v59_topsoilc_crop_steadystate(j2, sPools59, w, tillage59)  =e=     
+    sum(kcr_tillage59(kcr, tillage59), vm_res_recycling(j2, kcr, w, "c") * 
+                                         i59_cinput_multiplier_residue(j2, sPools59, kcr)) /
+        sum(ct, f59_topsoilc_decay(ct, j2, sPools59, w, tillage59));
+
+*' as well as for all non cropland via
+                                  
+q59_steadystate_term_noncrop(j2, noncropland59, sPools59) ..  
+  v59_topsoilc_noncrop_steadystate(j2, noncropland59, sPools59)  =e=        
+    sum(ct, f59_litter_input(ct, j2, sPools59) /
+            f59_topsoilc_decay(ct, j2, sPools59, "rainfed", "notill")) *
+       vm_land(j2, noncropland59);
+
+*' To account for land-use transitions the previous carbon stocks has to be adjusted
+*' to calculate the new actual carbon stocks. Previous stocks are thus given by   
+*' the carbons stocks of current cropland plus the carbon offset (plus or minus) 
+*' from area being non-cropland in the time step before. 
+*' For cropland the previous SOC state after accounting for transitions is given by
+
+q59_previousstate_term_crop(j2, sPools59, w, tillage59) ..
+  v59_topsoilc_crop_previousstate(j2, sPools59, w, tillage59)     
+    =e= sum(ct, p59_topsoilc_density_pre(ct, j2, "crop", sPools59) *
+            sum(kcr_tillage59(kcr, tillage59), vm_area(j2, kcr, w))) +
+           sum((ct, noncropland59), (p59_topsoilc_density_pre(ct, j2, noncropland59, sPools59) -
+                                    p59_topsoilc_density_pre(ct, j2, "crop", sPools59)) *
+            v59_cropland_transitions(j2, tillage59, w, noncropland59));  
+
+*' with v59_cropland_transitions being a helper variable that translates cropland transitions
+*' in to tillage- and irrigation-type-specific SOC transfers via  
+*** STILL TO FIX
+
+q59_lutransitions_to_cropareas(j2, noncropland59) ..
+  sum((tillage59, w), v59_cropland_transitions(j2, tillage59, w, noncropland59)) =e=
+                          vm_lu_transitions(j2, noncropland59, "crop");
+
+*' The previous SOC state on non-cropland after accounting for land-use transition is not 
+*' tillage- and irrgations-type-specific and thus given by
+
+q59_previousstate_term_noncrop(j2, noncropland59, sPools59) ..
+  v59_topsoilc_noncrop_previousstate(j2, noncropland59, sPools59)
+    =e= sum((ct, land_from), p59_topsoilc_density_pre(ct, j2, land_from, sPools59) *
+            vm_lu_transitions(j2, land_from, noncropland59));
+ 
+*' Following the 2019-Refinement of the IPCC guidelines 2006 for cropland the actual state
+*' can be calculated via
+
+q59_actualstate_crop(j2, sPools59) ..
+               v59_topsoilc_actualstate(j2, "crop", sPools59)
+               =e= sum((tillage59, w), v59_topsoilc_crop_previousstate(j2, sPools59, w, tillage59) * 
+                        (1 - pc59_topsoilc_decay_timestep(j2, sPools59, w, tillage59))) +
+                   sum((tillage59, w), v59_topsoilc_crop_steadystate(j2, sPools59, w, tillage59) *
+                        pc59_topsoilc_decay_timestep(j2, sPools59, w, tillage59))
+               ;
+
+*' for cropland and via
+               
+q59_actualstate_noncrop(j2, noncropland59, sPools59) ..
+               v59_topsoilc_actualstate(j2, noncropland59, sPools59)
+               =e= v59_topsoilc_noncrop_previousstate(j2, noncropland59, sPools59) *
+                        (1 - pc59_topsoilc_decay_timestep(j2, sPools59, "rainfed", "notill")) +
+                   v59_topsoilc_noncrop_steadystate(j2, noncropland59, sPools59) *
+                        pc59_topsoilc_decay_timestep(j2, sPools59, "rainfed", "notill")
+              ;
+
+*' for non-cropland.
+
+*' The soil carbon content of the whole soil profile is than calculated as sum of actual topsoil pool
+*' and the reference soil carbon pool of the subsoil, that is assumed to be unaffected by human management:
+
+q59_carbon_soil(j2, land, stockType) ..
+                vm_carbon_stock(j2, land, "soilc", stockType)
+                =e= sum(sPools59, v59_topsoilc_actualstate(j2, land, sPools59)) + 
+                    vm_land(j2, land) * sum(ct, i59_subsoilc_density(ct, j2));
+
+*' Note, that as long as the three pool soil model is on regional scale, cluster scale soil carbon stocks 
+*' are not meaningful.
+
+*' The annual nitrogen release (or sink) for cropland soils is than 
+*' calculated by the loss of soil organic carbon given by
+
+q59_nr_som(i2) ..
+             vm_nr_som(i2)
+               =e= sum(cell(i2,j2), 1/m_timestep_length_forestry * 1/15 * sum((tillage59, w, sPools59), 
+                        (v59_topsoilc_crop_previousstate(j2, sPools59, w, tillage59) -
+                         v59_topsoilc_crop_steadystate(j2, sPools59, w, tillage59))
+                        * pc59_topsoilc_decay_timestep(j2, sPools59, w, tillage59)))
+              ;
+
+*' with the carbon to nitrogen ratio of soils assumed to be 15:1.
+
+*' The amount of nitrogen that becomes available to cropland farming is 
+*' limited by loss of soil organic matter by
+
+q59_nr_som_fertilizer(i2) ..
+          vm_nr_som_fertilizer(i2)
+          =l=
+          vm_nr_som(i2);
+
+*' as well as by the amount that crops can take up
+
+q59_nr_som_fertilizer2(i2) ..
+          vm_nr_som_fertilizer(i2)
+          =l=
+          sum(cell(i2,j2), vm_landexpansion(j2,"crop")) * s59_nitrogen_uptake;
+
+*' Here we assume a maximum of 200 kg on the expanded area.
diff --git a/modules/59_som/threepool_cell_apr25/input.gms b/modules/59_som/threepool_cell_apr25/input.gms
new file mode 100644
index 0000000000..9fb9092a3e
--- /dev/null
+++ b/modules/59_som/threepool_cell_apr25/input.gms
@@ -0,0 +1,82 @@
+*** |  (C) 2008-2023 Potsdam Institute for Climate Impact Research (PIK)
+*** |  authors, and contributors see CITATION.cff file. This file is part
+*** |  of MAgPIE and licensed under AGPL-3.0-or-later. Under Section 7 of
+*** |  AGPL-3.0, you are granted additional permissions described in the
+*** |  MAgPIE License Exception, version 1.0 (see LICENSE file).
+*** |  Contact: magpie@pik-potsdam.de
+
+scalars
+  s59_nitrogen_uptake  Maximum plant available nitrogen from soil organic matter loss (tN per ha)        / 0.2 /
+;
+
+$setglobal c59_som_scenario  cc
+*   options:  cc        (climate change)
+*             nocc      (no climate change)
+*             nocc_hist (no climate change after year defined by sm_fix_cc)
+
+parameters f59_topsoilc_density(t_all,j) LPJ topsoil carbon density for natural vegetation (tC per ha)
+/
+$ondelim
+$include "./modules/59_som/input/lpj_carbon_topsoil.cs2b"
+$offdelim
+/
+;
+$if "%c59_som_scenario%" == "nocc" f59_topsoilc_density(t_all,j) = f59_topsoilc_density("y1995",j);
+$if "%c59_som_scenario%" == "nocc_hist" f59_topsoilc_density(t_all,j)$(m_year(t_all) > sm_fix_cc) = f59_topsoilc_density(t_all,j)$(m_year(t_ai) = sm_fix_cc);
+m_fillmissingyears(f59_topsoilc_density,"j");
+
+
+table f59_cinput_multiplier_residue(j,sPools59,kcr,tillage59) LPJ topsoil carbon density for natural vegetation (tC per ha)
+$ondelim
+$include "./modules/59_som/threepool_cell_apr25/input/f59_cinput_multiplier_residue.cs3"
+$offdelim
+;
+
+table f59_cinput_multiplier_manure(j,sPools59,kli,tillage59) LPJ topsoil carbon density for natural vegetation (tC per ha)
+$ondelim
+$include "./modules/59_som/threepool_cell_apr25/input/f59_cinput_multiplier_manure.cs3"
+$offdelim
+;
+
+
+table f59_litter_input(t_all,j,sPools59) LPJ topsoil carbon density for natural vegetation (tC per ha)
+$ondelim
+$include "./modules/59_som/threepool_cell_apr25/input/f59_litter_input.cs3"
+$offdelim
+;
+$if "%c59_som_scenario%" == "nocc" 
+  f59_litter_input(t_all,j,sPools59) = f59_litter_input("y1995",j,sPools59);
+$if "%c59_som_scenario%" == "nocc_hist" 
+  f59_litter_input(t_all,j,sPools59)$(m_year(t_all) > sm_fix_cc) = f59_litter_input(t_all,j,sPools59)$(m_year(t_ai) = sm_fix_cc);
+m_fillmissingyears(f59_litter_input,"j,sPools59");
+
+
+table f59_topsoilc_decay(t_all,j,sPools59,w,tillage59) Soil decay rates for all SOC sub-pools per year (1)
+$ondelim
+$include "./modules/59_som/threepool_cell_apr25/input/f59_topsoilc_decay.cs3"
+$offdelim
+;
+$if "%c59_som_scenario%" == "nocc" 
+  f59_topsoilc_decay(t_all,j,sPools59,w,tillage59) = f59_topsoilc_decay("y1995",j,sPools59,w,tillage59);
+$if "%c59_som_scenario%" == "nocc_hist" 
+  f59_topsoilc_decay(t_all,j,sPools59,w,tillage59)$(m_year(t_all) > sm_fix_cc) = f59_topsoilc_decay(t_all,j,sPools59,w,tillage59)$(m_year(t_ai) = sm_fix_cc);
+m_fillmissingyears(f59_topsoilc_decay,"j,sPools59,w,tillage59");
+
+
+table f59_topsoilc_actualstate(j,sPools59,lutypes59) LPJ topsoil carbon for different pools and lu types(million tC)
+$ondelim 
+$include "./modules/59_som/threepool_cell_apr25/input/f59_topsoilc_actualstate.cs3"
+$offdelim
+;
+
+table f59_topsoilc_naturalstate(j,sPools59,lutypes59) LPJ natural topsoil carbon for different pools and lu types(million tC)
+$ondelim
+$include "./modules/59_som/threepool_cell_apr25/input/f59_topsoilc_naturalstate.cs3"
+$offdelim
+;
+
+table f59_land_y1990(t_pre59,j,land) land use in y1990 (million ha)
+$ondelim
+$include "./modules/59_som/threepool_cell_apr25/input/f59_land_y1990.cs3"
+$offdelim
+;
diff --git a/modules/59_som/threepool_cell_apr25/input/files b/modules/59_som/threepool_cell_apr25/input/files
new file mode 100644
index 0000000000..683cbbe074
--- /dev/null
+++ b/modules/59_som/threepool_cell_apr25/input/files
@@ -0,0 +1,8 @@
+* list of files that are required here
+f59_land_y1990.cs3
+f59_cinput_multiplier_residue.cs3
+f59_cinput_multiplier_manure.cs3
+f59_litter_input.cs3
+f59_topsoilc_decay.cs3
+f59_topsoilc_actualstate.cs3
+f59_topsoilc_naturalstate.cs3
diff --git a/modules/59_som/threepool_cell_apr25/not_used.txt b/modules/59_som/threepool_cell_apr25/not_used.txt
new file mode 100644
index 0000000000..1d37eb479c
--- /dev/null
+++ b/modules/59_som/threepool_cell_apr25/not_used.txt
@@ -0,0 +1,7 @@
+name,type,reason
+fm_croparea,input,questionnaire
+pm_climate_class,input,questionnaire
+vm_fallow,input,questionnaire
+vm_treecover,input,not_used
+vm_land_other,input,not_used
+pm_avl_cropland_iso,input,nou_used
diff --git a/modules/59_som/threepool_cell_apr25/postsolve.gms b/modules/59_som/threepool_cell_apr25/postsolve.gms
new file mode 100644
index 0000000000..51826b9c06
--- /dev/null
+++ b/modules/59_som/threepool_cell_apr25/postsolve.gms
@@ -0,0 +1,111 @@
+*** |  (C) 2008-2023 Potsdam Institute for Climate Impact Research (PIK)
+*** |  authors, and contributors see CITATION.cff file. This file is part
+*** |  of MAgPIE and licensed under AGPL-3.0-or-later. Under Section 7 of
+*** |  AGPL-3.0, you are granted additional permissions described in the
+*** |  MAgPIE License Exception, version 1.0 (see LICENSE file).
+*** |  Contact: magpie@pik-potsdam.de
+
+p59_topsoilc_actualstate(j, land, sPools59) = v59_topsoilc_actualstate.l(j, land, sPools59);
+p59_topsoilc_density_post(t, j, land, sPools59)$(pcm_land(j,land) > 1e-10) = 
+  p59_topsoilc_actualstate(j, land, sPools59) / pcm_land(j,land);
+p59_land_before(j,land) = vm_land.l(j,land);
+
+**** natural stock calculations
+
+pc59_topsoilc_natural_steadystate(j, land, sPools59) =
+     f59_litter_input(t, j, sPools59) /
+       f59_topsoilc_decay(t, j, sPools59, "rainfed", "notill") *
+        vm_land.l(j, land);
+
+p59_topsoilc_naturalstate(t, j, land, sPools59)  = 
+     pc59_topsoilc_naturalstate_previous(j, land, sPools59) *
+       (1 - pc59_topsoilc_decay_timestep(j, sPools59, "rainfed", "notill")) +
+         pc59_topsoilc_natural_steadystate(j, land, sPools59) *
+           pc59_topsoilc_decay_timestep(j, sPools59, "rainfed", "notill");
+
+
+pc59_topsoilc_naturalstate_previous(j, land, sPools59) =
+  p59_topsoilc_naturalstate(t, j, land, sPools59);
+
+*#################### R SECTION START (OUTPUT DEFINITIONS) #####################
+ ov59_topsoilc_crop_steadystate(t,j,sPools59,w,tillage59,"marginal")        = v59_topsoilc_crop_steadystate.m(j,sPools59,w,tillage59);
+ ov59_topsoilc_noncrop_steadystate(t,j,noncropland59,sPools59,"marginal")   = v59_topsoilc_noncrop_steadystate.m(j,noncropland59,sPools59);
+ ov59_topsoilc_crop_previousstate(t,j,sPools59,w,tillage59,"marginal")      = v59_topsoilc_crop_previousstate.m(j,sPools59,w,tillage59);
+ ov59_cropland_transitions(t,j,tillage59,w,noncropland59,"marginal")        = v59_cropland_transitions.m(j,tillage59,w,noncropland59);
+ ov59_topsoilc_noncrop_previousstate(t,j,noncropland59,sPools59,"marginal") = v59_topsoilc_noncrop_previousstate.m(j,noncropland59,sPools59);
+ ov59_topsoilc_actualstate(t,j,land,sPools59,"marginal")                    = v59_topsoilc_actualstate.m(j,land,sPools59);
+ ov_cost_scm(t,j,"marginal")                                                = vm_cost_scm.m(j);
+ ov_nr_som(t,j,"marginal")                                                  = vm_nr_som.m(i);
+ ov_nr_som_fertilizer(t,j,"marginal")                                       = vm_nr_som_fertilizer.m(i);
+ oq59_steadystate_term_crop(t,j,sPools59,w,tillage59,"marginal")            = q59_steadystate_term_crop.m(j,sPools59,w,tillage59);
+ oq59_previousstate_term_crop(t,j,sPools59,w,tillage59,"marginal")          = q59_previousstate_term_crop.m(j,sPools59,w,tillage59);
+ oq59_lutransitions_to_cropareas(t,j,noncropland59,"marginal")              = q59_lutransitions_to_cropareas.m(j,noncropland59);
+ oq59_actualstate_crop(t,j,sPools59,"marginal")                             = q59_actualstate_crop.m(j,sPools59);
+ oq59_steadystate_term_noncrop(t,j,noncropland59,sPools59,"marginal")       = q59_steadystate_term_noncrop.m(j,noncropland59,sPools59);
+ oq59_previousstate_term_noncrop(t,j,noncropland59,sPools59,"marginal")     = q59_previousstate_term_noncrop.m(j,noncropland59,sPools59);
+ oq59_actualstate_noncrop(t,j,noncropland59,sPools59,"marginal")            = q59_actualstate_noncrop.m(j,noncropland59,sPools59);
+ oq59_carbon_soil(t,j,land,stockType,"marginal")                            = q59_carbon_soil.m(j,land,stockType);
+ oq59_nr_som(t,j,"marginal")                                                = q59_nr_som.m(i);
+ oq59_nr_som_fertilizer2(t,j,"marginal")                                    = q59_nr_som_fertilizer2.m(i);
+ oq59_nr_som_fertilizer(t,j,"marginal")                                     = q59_nr_som_fertilizer.m(i);
+ ov59_topsoilc_crop_steadystate(t,j,sPools59,w,tillage59,"level")           = v59_topsoilc_crop_steadystate.l(j,sPools59,w,tillage59);
+ ov59_topsoilc_noncrop_steadystate(t,j,noncropland59,sPools59,"level")      = v59_topsoilc_noncrop_steadystate.l(j,noncropland59,sPools59);
+ ov59_topsoilc_crop_previousstate(t,j,sPools59,w,tillage59,"level")         = v59_topsoilc_crop_previousstate.l(j,sPools59,w,tillage59);
+ ov59_cropland_transitions(t,j,tillage59,w,noncropland59,"level")           = v59_cropland_transitions.l(j,tillage59,w,noncropland59);
+ ov59_topsoilc_noncrop_previousstate(t,j,noncropland59,sPools59,"level")    = v59_topsoilc_noncrop_previousstate.l(j,noncropland59,sPools59);
+ ov59_topsoilc_actualstate(t,j,land,sPools59,"level")                       = v59_topsoilc_actualstate.l(j,land,sPools59);
+ ov_cost_scm(t,j,"level")                                                   = vm_cost_scm.l(j);
+ ov_nr_som(t,j,"level")                                                     = vm_nr_som.l(i);
+ ov_nr_som_fertilizer(t,j,"level")                                          = vm_nr_som_fertilizer.l(i);
+ oq59_steadystate_term_crop(t,j,sPools59,w,tillage59,"level")               = q59_steadystate_term_crop.l(j,sPools59,w,tillage59);
+ oq59_previousstate_term_crop(t,j,sPools59,w,tillage59,"level")             = q59_previousstate_term_crop.l(j,sPools59,w,tillage59);
+ oq59_lutransitions_to_cropareas(t,j,noncropland59,"level")                 = q59_lutransitions_to_cropareas.l(j,noncropland59);
+ oq59_actualstate_crop(t,j,sPools59,"level")                                = q59_actualstate_crop.l(j,sPools59);
+ oq59_steadystate_term_noncrop(t,j,noncropland59,sPools59,"level")          = q59_steadystate_term_noncrop.l(j,noncropland59,sPools59);
+ oq59_previousstate_term_noncrop(t,j,noncropland59,sPools59,"level")        = q59_previousstate_term_noncrop.l(j,noncropland59,sPools59);
+ oq59_actualstate_noncrop(t,j,noncropland59,sPools59,"level")               = q59_actualstate_noncrop.l(j,noncropland59,sPools59);
+ oq59_carbon_soil(t,j,land,stockType,"level")                               = q59_carbon_soil.l(j,land,stockType);
+ oq59_nr_som(t,j,"level")                                                   = q59_nr_som.l(i);
+ oq59_nr_som_fertilizer2(t,j,"level")                                       = q59_nr_som_fertilizer2.l(i);
+ oq59_nr_som_fertilizer(t,j,"level")                                        = q59_nr_som_fertilizer.l(i);
+ ov59_topsoilc_crop_steadystate(t,j,sPools59,w,tillage59,"upper")           = v59_topsoilc_crop_steadystate.up(j,sPools59,w,tillage59);
+ ov59_topsoilc_noncrop_steadystate(t,j,noncropland59,sPools59,"upper")      = v59_topsoilc_noncrop_steadystate.up(j,noncropland59,sPools59);
+ ov59_topsoilc_crop_previousstate(t,j,sPools59,w,tillage59,"upper")         = v59_topsoilc_crop_previousstate.up(j,sPools59,w,tillage59);
+ ov59_cropland_transitions(t,j,tillage59,w,noncropland59,"upper")           = v59_cropland_transitions.up(j,tillage59,w,noncropland59);
+ ov59_topsoilc_noncrop_previousstate(t,j,noncropland59,sPools59,"upper")    = v59_topsoilc_noncrop_previousstate.up(j,noncropland59,sPools59);
+ ov59_topsoilc_actualstate(t,j,land,sPools59,"upper")                       = v59_topsoilc_actualstate.up(j,land,sPools59);
+ ov_cost_scm(t,j,"upper")                                                   = vm_cost_scm.up(j);
+ ov_nr_som(t,j,"upper")                                                     = vm_nr_som.up(i);
+ ov_nr_som_fertilizer(t,j,"upper")                                          = vm_nr_som_fertilizer.up(i);
+ oq59_steadystate_term_crop(t,j,sPools59,w,tillage59,"upper")               = q59_steadystate_term_crop.up(j,sPools59,w,tillage59);
+ oq59_previousstate_term_crop(t,j,sPools59,w,tillage59,"upper")             = q59_previousstate_term_crop.up(j,sPools59,w,tillage59);
+ oq59_lutransitions_to_cropareas(t,j,noncropland59,"upper")                 = q59_lutransitions_to_cropareas.up(j,noncropland59);
+ oq59_actualstate_crop(t,j,sPools59,"upper")                                = q59_actualstate_crop.up(j,sPools59);
+ oq59_steadystate_term_noncrop(t,j,noncropland59,sPools59,"upper")          = q59_steadystate_term_noncrop.up(j,noncropland59,sPools59);
+ oq59_previousstate_term_noncrop(t,j,noncropland59,sPools59,"upper")        = q59_previousstate_term_noncrop.up(j,noncropland59,sPools59);
+ oq59_actualstate_noncrop(t,j,noncropland59,sPools59,"upper")               = q59_actualstate_noncrop.up(j,noncropland59,sPools59);
+ oq59_carbon_soil(t,j,land,stockType,"upper")                               = q59_carbon_soil.up(j,land,stockType);
+ oq59_nr_som(t,j,"upper")                                                   = q59_nr_som.up(i);
+ oq59_nr_som_fertilizer2(t,j,"upper")                                       = q59_nr_som_fertilizer2.up(i);
+ oq59_nr_som_fertilizer(t,j,"upper")                                        = q59_nr_som_fertilizer.up(i);
+ ov59_topsoilc_crop_steadystate(t,j,sPools59,w,tillage59,"lower")           = v59_topsoilc_crop_steadystate.lo(j,sPools59,w,tillage59);
+ ov59_topsoilc_noncrop_steadystate(t,j,noncropland59,sPools59,"lower")      = v59_topsoilc_noncrop_steadystate.lo(j,noncropland59,sPools59);
+ ov59_topsoilc_crop_previousstate(t,j,sPools59,w,tillage59,"lower")         = v59_topsoilc_crop_previousstate.lo(j,sPools59,w,tillage59);
+ ov59_cropland_transitions(t,j,tillage59,w,noncropland59,"lower")           = v59_cropland_transitions.lo(j,tillage59,w,noncropland59);
+ ov59_topsoilc_noncrop_previousstate(t,j,noncropland59,sPools59,"lower")    = v59_topsoilc_noncrop_previousstate.lo(j,noncropland59,sPools59);
+ ov59_topsoilc_actualstate(t,j,land,sPools59,"lower")                       = v59_topsoilc_actualstate.lo(j,land,sPools59);
+ ov_cost_scm(t,j,"lower")                                                   = vm_cost_scm.lo(j);
+ ov_nr_som(t,j,"lower")                                                     = vm_nr_som.lo(i);
+ ov_nr_som_fertilizer(t,j,"lower")                                          = vm_nr_som_fertilizer.lo(i);
+ oq59_steadystate_term_crop(t,j,sPools59,w,tillage59,"lower")               = q59_steadystate_term_crop.lo(j,sPools59,w,tillage59);
+ oq59_previousstate_term_crop(t,j,sPools59,w,tillage59,"lower")             = q59_previousstate_term_crop.lo(j,sPools59,w,tillage59);
+ oq59_lutransitions_to_cropareas(t,j,noncropland59,"lower")                 = q59_lutransitions_to_cropareas.lo(j,noncropland59);
+ oq59_actualstate_crop(t,j,sPools59,"lower")                                = q59_actualstate_crop.lo(j,sPools59);
+ oq59_steadystate_term_noncrop(t,j,noncropland59,sPools59,"lower")          = q59_steadystate_term_noncrop.lo(j,noncropland59,sPools59);
+ oq59_previousstate_term_noncrop(t,j,noncropland59,sPools59,"lower")        = q59_previousstate_term_noncrop.lo(j,noncropland59,sPools59);
+ oq59_actualstate_noncrop(t,j,noncropland59,sPools59,"lower")               = q59_actualstate_noncrop.lo(j,noncropland59,sPools59);
+ oq59_carbon_soil(t,j,land,stockType,"lower")                               = q59_carbon_soil.lo(j,land,stockType);
+ oq59_nr_som(t,j,"lower")                                                   = q59_nr_som.lo(i);
+ oq59_nr_som_fertilizer2(t,j,"lower")                                       = q59_nr_som_fertilizer2.lo(i);
+ oq59_nr_som_fertilizer(t,j,"lower")                                        = q59_nr_som_fertilizer.lo(i);
+*##################### R SECTION END (OUTPUT DEFINITIONS) ######################
diff --git a/modules/59_som/threepool_cell_apr25/preloop.gms b/modules/59_som/threepool_cell_apr25/preloop.gms
new file mode 100644
index 0000000000..8313f47e2b
--- /dev/null
+++ b/modules/59_som/threepool_cell_apr25/preloop.gms
@@ -0,0 +1,33 @@
+*** |  (C) 2008-2023 Potsdam Institute for Climate Impact Research (PIK)
+*** |  authors, and contributors see CITATION.cff file. This file is part
+*** |  of MAgPIE and licensed under AGPL-3.0-or-later. Under Section 7 of
+*** |  AGPL-3.0, you are granted additional permissions described in the
+*** |  MAgPIE License Exception, version 1.0 (see LICENSE file).
+*** |  Contact: magpie@pik-potsdam.de
+
+
+*****************************
+*** SOC initialisation    ***
+*****************************
+
+i59_subsoilc_density(t_all, j) = 
+  fm_carbon_density(t_all, j, "secdforest", "soilc") - f59_topsoilc_density(t_all, j);
+  
+
+pcm_carbon_stock(j, land, "soilc", stockType) = 
+ fm_carbon_density("y1995", j, land, "soilc") * pm_land_start(j, land);
+
+vm_carbon_stock.l(j, land, "soilc", stockType) =
+  pcm_carbon_stock(j, land, "soilc", stockType);
+
+p59_land_before(j,land) = pm_land_start(j,land);
+
+*****************************
+*** parameter dummies     ***
+*****************************
+
+i59_cinput_multiplier_residue(j,sPools59,kcr) = 
+  sum(kcr2$(sameas(kcr,kcr2)), 
+    sum(kcr_tillage59(kcr2,tillage59), 
+      f59_cinput_multiplier_residue(j,sPools59,kcr,tillage59)));
+
diff --git a/modules/59_som/threepool_cell_apr25/presolve.gms b/modules/59_som/threepool_cell_apr25/presolve.gms
new file mode 100644
index 0000000000..b82c033dda
--- /dev/null
+++ b/modules/59_som/threepool_cell_apr25/presolve.gms
@@ -0,0 +1,65 @@
+*** |  (C) 2008-2023 Potsdam Institute for Climate Impact Research (PIK)
+*** |  authors, and contributors see CITATION.cff file. This file is part
+*** |  of MAgPIE and licensed under AGPL-3.0-or-later. Under Section 7 of
+*** |  AGPL-3.0, you are granted additional permissions described in the
+*** |  MAgPIE License Exception, version 1.0 (see LICENSE file).
+*** |  Contact: magpie@pik-potsdam.de
+
+vm_cost_scm.fx(j) = 0;
+
+* For the first time steps:
+* Initializating of SOC pools in the different land types using the input from mrsoil
+
+* For all other time steps:
+* SOM pools and densities will be updated after natural regrowth and disturbance loss accounting.
+* The secondary forest pool will receive carbon from primary forest (due to natural disturbance)
+* and from other land (due to regrowth).
+* Note: This will only account for transitions of primary forest to secondary forest and
+* other land to secondary forest. See current version of 35_natveg to check consistency.
+* The helper parameter `p59_topsoilc_actualstate` is used  to update `p59_topsoilc_density_pre`
+
+i59_topsoilc_decay_max1(t, j, sPools59, w, tillage59) =
+  min(1, f59_topsoilc_decay(t, j, sPools59, w, tillage59));
+
+pc59_topsoilc_decay_timestep(j, sPools59, w, tillage59) = 
+  1 - (1 - i59_topsoilc_decay_max1(t, j, sPools59, w, tillage59)) ** m_yeardiff_forestry(t);
+
+if((ord(t) = 1),
+
+  p59_topsoilc_density_pre("y1995", j, land, sPools59) =
+    sum(lutypes59_land(land, lutypes59),
+      f59_topsoilc_actualstate(j, sPools59, lutypes59)  /
+        sum(lutypes59_land2(land2,lutypes59), f59_land_y1990("y1990", j, land2)));
+
+  p59_topsoilc_density_post(t, j, land, sPools59) = 0;
+  p59_topsoilc_actualstate(j, land, sPools59) = 0;
+
+  pc59_topsoilc_naturalstate_previous(j, land, sPools59) = 
+    sum(lutypes59_land(land, lutypes59),
+      f59_topsoilc_naturalstate(j, sPools59, lutypes59)  /
+        sum(lutypes59_land2(land2,lutypes59), f59_land_y1990("y1990", j, land2))) * 
+          f59_land_y1990("y1990", j, land);
+ 
+else
+
+  p59_topsoilc_actualstate(j, "secdforest", sPools59) = 
+    p59_topsoilc_actualstate(j, "secdforest", sPools59) + 
+    (p59_land_before(j, "primforest") - pcm_land(j, "primforest")) *
+      p59_topsoilc_density_post(t-1, j, "primforest", sPools59) + 
+    (p59_land_before(j, "other") - pcm_land(j, "other")) *
+      p59_topsoilc_density_post(t-1, j, "other", sPools59);
+
+  p59_topsoilc_actualstate(j, "other", sPools59) = 
+    p59_topsoilc_actualstate(j, "other", sPools59) - 
+    (p59_land_before(j, "other") - pcm_land(j, "other")) *
+      p59_topsoilc_density_post(t-1, j, "other", sPools59);
+
+  p59_topsoilc_actualstate(j, "primforest", sPools59) = 
+    p59_topsoilc_actualstate(j, "primforest", sPools59) - 
+    (p59_land_before(j, "primforest") - pcm_land(j, "primforest")) *
+      p59_topsoilc_density_post(t-1, j, "primforest", sPools59);
+
+  p59_topsoilc_density_pre(t, j, land, sPools59)$(pcm_land(j,land) > 1e-20) =
+    p59_topsoilc_actualstate(j, land, sPools59) / pcm_land(j,land);
+
+);
diff --git a/modules/59_som/threepool_cell_apr25/realization.gms b/modules/59_som/threepool_cell_apr25/realization.gms
new file mode 100644
index 0000000000..ddea7638b1
--- /dev/null
+++ b/modules/59_som/threepool_cell_apr25/realization.gms
@@ -0,0 +1,27 @@
+*** |  (C) 2008-2023 Potsdam Institute for Climate Impact Research (PIK)
+*** |  authors, and contributors see CITATION.cff file. This file is part
+*** |  of MAgPIE and licensed under AGPL-3.0-or-later. Under Section 7 of
+*** |  AGPL-3.0, you are granted additional permissions described in the
+*** |  MAgPIE License Exception, version 1.0 (see LICENSE file).
+*** |  Contact: magpie@pik-potsdam.de
+
+*' @description
+*' The threepool_may23 realization is based on the Tier 2 approach of the revised IPCC 
+*' Guidelines for National Greenhouse Gas Inventories 2019 (@calvo_buendia_ipcc_2019). 
+*' It calculates the stock of soil carbon for all land-use types based on a reduced complexity 
+*' soil model driven by carbon inputs and decay rates depending on management decisions. 
+
+*' @limitations tba
+
+*' @authors Kristine Karstens
+
+*####################### R SECTION START (PHASES) ##############################
+$Ifi "%phase%" == "sets" $include "./modules/59_som/threepool_may23/sets.gms"
+$Ifi "%phase%" == "declarations" $include "./modules/59_som/threepool_may23/declarations.gms"
+$Ifi "%phase%" == "input" $include "./modules/59_som/threepool_may23/input.gms"
+$Ifi "%phase%" == "equations" $include "./modules/59_som/threepool_may23/equations.gms"
+$Ifi "%phase%" == "scaling" $include "./modules/59_som/threepool_may23/scaling.gms"
+$Ifi "%phase%" == "preloop" $include "./modules/59_som/threepool_may23/preloop.gms"
+$Ifi "%phase%" == "presolve" $include "./modules/59_som/threepool_may23/presolve.gms"
+$Ifi "%phase%" == "postsolve" $include "./modules/59_som/threepool_may23/postsolve.gms"
+*######################## R SECTION END (PHASES) ###############################
diff --git a/modules/59_som/threepool_cell_apr25/scaling.gms b/modules/59_som/threepool_cell_apr25/scaling.gms
new file mode 100644
index 0000000000..dc08cc3205
--- /dev/null
+++ b/modules/59_som/threepool_cell_apr25/scaling.gms
@@ -0,0 +1,12 @@
+*** |  (C) 2008-2024 Potsdam Institute for Climate Impact Research (PIK)
+*** |  authors, and contributors see CITATION.cff file. This file is part
+*** |  of MAgPIE and licensed under AGPL-3.0-or-later. Under Section 7 of
+*** |  AGPL-3.0, you are granted additional permissions described in the
+*** |  MAgPIE License Exception, version 1.0 (see LICENSE file).
+*** |  Contact: magpie@pik-potsdam.de
+
+v59_topsoilc_crop_steadystate.scale(j,sPools59,w,tillage59) = 10e4;      
+v59_topsoilc_noncrop_steadystate.scale(j,noncropland59,sPools59) = 10e4;  
+v59_topsoilc_crop_previousstate.scale(j,sPools59,w,tillage59) = 10e4;     
+v59_topsoilc_noncrop_previousstate.scale(j,noncropland59,sPools59) = 10e4;
+v59_topsoilc_actualstate.scale(j,land,sPools59) = 10e4; 
diff --git a/modules/59_som/threepool_cell_apr25/sets.gms b/modules/59_som/threepool_cell_apr25/sets.gms
new file mode 100644
index 0000000000..2d9698275e
--- /dev/null
+++ b/modules/59_som/threepool_cell_apr25/sets.gms
@@ -0,0 +1,63 @@
+*** |  (C) 2008-2023 Potsdam Institute for Climate Impact Research (PIK)
+*** |  authors, and contributors see CITATION.cff file. This file is part
+*** |  of MAgPIE and licensed under AGPL-3.0-or-later. Under Section 7 of
+*** |  AGPL-3.0, you are granted additional permissions described in the
+*** |  MAgPIE License Exception, version 1.0 (see LICENSE file).
+*** |  Contact: magpie@pik-potsdam.de
+
+sets
+
+t_pre59  Year of the previous time step
+       / y1990 /
+
+sPools59 soil pools
+/ active, slow, passive /
+
+noncropland59(land) Soil carbon conserving landuse types
+/ past, forestry, primforest, secdforest, other, urban /
+
+tillage59 Tillage categories of IPCC
+/ fulltill, reducedtill, notill /
+
+lutypes59 Land-use types 
+/ crop, natveg /
+
+kcr_tillage59(kcr,tillage59) Climate classification types
+           /
+           begr      .(reducedtill) "reduced tillage"
+           betr      .(reducedtill) "reduced tillage"
+           cassav_sp .(fulltill) "full tillage"
+           cottn_pro .(fulltill) "full tillage"
+           foddr     .(fulltill) "full tillage"
+           groundnut .(fulltill) "full tillage"
+           maiz      .(fulltill) "full tillage"
+           oilpalm   .(reducedtill) "reduced tillage"
+           others    .(reducedtill) "reduced tillage"
+           potato    .(fulltill) "full tillage"
+           puls_pro  .(fulltill) "full tillage"
+           rapeseed  .(fulltill) "full tillage"
+           rice_pro  .(fulltill) "full tillage"
+           soybean   .(fulltill) "full tillage"
+           sugr_beet .(fulltill) "full tillage"
+           sugr_cane .(reducedtill) "reduced tillage"
+           sunflower .(fulltill) "full tillage"
+           tece      .(fulltill) "full tillage"
+           trce      .(fulltill) "full tillage"
+           /
+
+lutypes59_land(land,lutypes59) Mapping land to soil model land classes
+           /
+           crop       .(crop)   "cropland"
+           past       .(natveg) "potential natural vegetation"
+           forestry   .(natveg) "potential natural vegetation"
+           primforest .(natveg) "potential natural vegetation"
+           secdforest .(natveg) "potential natural vegetation"
+           other      .(natveg) "potential natural vegetation"
+           urban      .(natveg) "potential natural vegetation"
+           / 
+;
+
+alias(noncropland59,noncropland59_2);
+alias(land,land2);
+alias(lutypes59_land,lutypes59_land2);
+alias(kcr,kcr2);
diff --git a/modules/59_som/threepool_reg_may23/declarations.gms b/modules/59_som/threepool_reg_may23/declarations.gms
new file mode 100644
index 0000000000..748dbde2ae
--- /dev/null
+++ b/modules/59_som/threepool_reg_may23/declarations.gms
@@ -0,0 +1,74 @@
+*** |  (C) 2008-2023 Potsdam Institute for Climate Impact Research (PIK)
+*** |  authors, and contributors see CITATION.cff file. This file is part
+*** |  of MAgPIE and licensed under AGPL-3.0-or-later. Under Section 7 of
+*** |  AGPL-3.0, you are granted additional permissions described in the
+*** |  MAgPIE License Exception, version 1.0 (see LICENSE file).
+*** |  Contact: magpie@pik-potsdam.de
+
+parameters
+          i59_cinput_multiplier_residue(i, sPools59, kcr)                 Carbon input to soil pool input multipliers (1)
+          i59_topsoilc_decay_max1(t, i, sPools59, w, tillage59)           Soil decay rates for all SOC sub-pools per year cut at 1 (1)
+          pc59_topsoilc_decay_timestep(i, sPools59, w, tillage59)         Soil decay rates for all SOC sub-pools per time steps length (1)
+          p59_topsoilc_density_pre(t_all, i, land, sPools59)              Soil carbon density of the upper layer per hectare before solve (tC per ha)
+          p59_topsoilc_density_post(t_all, i, land, sPools59)             Soil carbon density of the upper layer per hectare after solve (tC per ha)
+          p59_topsoilc_actualstate(i, land, sPools59)                     Actual soil carbon stock per land type (mio. tC)
+          p59_topsoilc_naturalstate(t_all, i, land, sPools59)             Natural soil carbon stock per land type (mio. tC)
+          pc59_topsoilc_natural_steadystate(i, land, sPools59)            Natural steady state soil carbon stpock (mio. tC)
+          pc59_topsoilc_naturalstate_previous(i, land, sPools59)          Natural state of the time step before (mio. tC)
+          i59_subsoilc_density(t_all,j)                                   Subsoil carbon density of per hectare (tC per ha)
+          p59_land_before(j,land)                                         Land area in previous time step (mio. ha)
+;
+
+equations
+         q59_steadystate_term_crop(i, sPools59, w, tillage59)                    Steady-state for SOC stock on cropland (mio. tC)
+         q59_previousstate_term_crop(i, sPools59, w, tillage59)               bla
+         q59_lutransitions_to_cropareas(i, noncropland59)                    bla
+         q59_actualstate_crop(i, sPools59)                                   bla
+         q59_steadystate_term_noncrop(i, noncropland59, sPools59)            bla
+         q59_previousstate_term_noncrop(i, noncropland59, sPools59)             Steady-state for SOC on various non-cropland types (mio. tC)
+         q59_actualstate_noncrop(i, noncropland59, sPools59)                 bla
+         q59_carbon_soil(i, land, stockType)                                 bla
+         q59_nr_som(i)                                                          bla
+         q59_nr_som_fertilizer2(i)                                              bla
+         q59_nr_som_fertilizer(i)                                               bla
+;
+
+positive variables
+         v59_topsoilc_crop_steadystate(i, sPools59, w, tillage59)             bla
+         v59_topsoilc_noncrop_steadystate(i, noncropland59, sPools59)        bla
+         v59_topsoilc_crop_previousstate(i, sPools59, w, tillage59)           bla
+         v59_cropland_transitions(i, tillage59, w, noncropland59)            bla
+         v59_topsoilc_noncrop_previousstate(i, noncropland59, sPools59)      bla
+         v59_topsoilc_actualstate(i, land, sPools59)                         bla
+        vm_cost_scm(j)                      Recurring cost for soil carbon management on cropland (mio. USD17MER per yr)
+;
+
+variables
+         vm_nr_som(i)                                       Release of soil organic matter (Mt N per yr)
+         vm_nr_som_fertilizer(i)                            Uptake of soil organic matter from plants (Mt N per yr)
+;
+
+*#################### R SECTION START (OUTPUT DECLARATIONS) ####################
+parameters
+ ov59_topsoilc_crop_steadystate(t,i,sPools59,w,tillage59,type)        bla
+ ov59_topsoilc_noncrop_steadystate(t,i,noncropland59,sPools59,type)   bla
+ ov59_topsoilc_crop_previousstate(t,i,sPools59,w,tillage59,type)      bla
+ ov59_cropland_transitions(t,i,tillage59,w,noncropland59,type)        bla
+ ov59_topsoilc_noncrop_previousstate(t,i,noncropland59,sPools59,type) bla
+ ov59_topsoilc_actualstate(t,i,land,sPools59,type)                    bla
+ ov_cost_scm(t,j,type)                                                Recurring cost for soil carbon management on cropland (mio. USD17MER per yr)
+ ov_nr_som(t,i,type)                                                  Release of soil organic matter (Mt N per yr)
+ ov_nr_som_fertilizer(t,i,type)                                       Uptake of soil organic matter from plants (Mt N per yr)
+ oq59_steadystate_term_crop(t,i,sPools59,w,tillage59,type)            Steady-state for SOC stock on cropland (mio. tC)
+ oq59_previousstate_term_crop(t,i,sPools59,w,tillage59,type)          bla
+ oq59_lutransitions_to_cropareas(t,i,noncropland59,type)              bla
+ oq59_actualstate_crop(t,i,sPools59,type)                             bla
+ oq59_steadystate_term_noncrop(t,i,noncropland59,sPools59,type)       bla
+ oq59_previousstate_term_noncrop(t,i,noncropland59,sPools59,type)     Steady-state for SOC on various non-cropland types (mio. tC)
+ oq59_actualstate_noncrop(t,i,noncropland59,sPools59,type)            bla
+ oq59_carbon_soil(t,i,land,stockType,type)                            bla
+ oq59_nr_som(t,i,type)                                                bla
+ oq59_nr_som_fertilizer2(t,i,type)                                    bla
+ oq59_nr_som_fertilizer(t,i,type)                                     bla
+;
+*##################### R SECTION END (OUTPUT DECLARATIONS) #####################
diff --git a/modules/59_som/threepool_reg_may23/equations.gms b/modules/59_som/threepool_reg_may23/equations.gms
new file mode 100644
index 0000000000..6951ec9ecc
--- /dev/null
+++ b/modules/59_som/threepool_reg_may23/equations.gms
@@ -0,0 +1,119 @@
+*** |  (C) 2008-2023 Potsdam Institute for Climate Impact Research (PIK)
+*** |  authors, and contributors see CITATION.cff file. This file is part
+*** |  of MAgPIE and licensed under AGPL-3.0-or-later. Under Section 7 of
+*** |  AGPL-3.0, you are granted additional permissions described in the
+*** |  MAgPIE License Exception, version 1.0 (see LICENSE file).
+*** |  Contact: magpie@pik-potsdam.de
+
+
+*' @equations
+
+*' For every cell a new equilibrium value for the soil organic carbon pool
+*' on cropland is calculated as the sum over all crop types and irrigation regimes via
+
+q59_steadystate_term_crop(i2, sPools59, w, tillage59) .. 
+  v59_topsoilc_crop_steadystate(i2, sPools59, w, tillage59)  =e=     
+    sum(kcr_tillage59(kcr, tillage59), vm_res_recycling(i2, kcr, w, "c") * 
+                                         i59_cinput_multiplier_residue(i2, sPools59, kcr)) /
+        sum(ct, f59_topsoilc_decay(ct, i2, sPools59, w, tillage59));
+
+*' as well as for all non cropland via
+                                  
+q59_steadystate_term_noncrop(i2, noncropland59, sPools59) ..  
+  v59_topsoilc_noncrop_steadystate(i2, noncropland59, sPools59)  =e=        
+    sum(ct, f59_litter_input(ct, i2, sPools59) /
+            f59_topsoilc_decay(ct, i2, sPools59, "rainfed", "notill")) *
+      sum(cell(i2,j2), vm_land(j2, noncropland59));
+
+*' To account for land-use transitions the previous carbon stocks has to be adjusted
+*' to calculate the new actual carbon stocks. Previous stocks are thus given by   
+*' the carbons stocks of current cropland plus the carbon offset (plus or minus) 
+*' from area being non-cropland in the time step before. 
+*' For cropland the previous SOC state after accounting for transitions is given by
+
+q59_previousstate_term_crop(i2, sPools59, w, tillage59) ..
+  v59_topsoilc_crop_previousstate(i2, sPools59, w, tillage59)     
+    =e= sum(ct, p59_topsoilc_density_pre(ct, i2, "crop", sPools59) *
+            sum((cell(i2, j2), kcr_tillage59(kcr, tillage59)), vm_area(j2, kcr, w))) +
+           sum((ct, noncropland59), (p59_topsoilc_density_pre(ct, i2, noncropland59, sPools59) -
+                                    p59_topsoilc_density_pre(ct, i2, "crop", sPools59)) *
+            v59_cropland_transitions(i2, tillage59, w, noncropland59));  
+
+*' with v59_cropland_transitions being a helper variable that translates cropland transitions
+*' in to tillage- and irrigation-type-specific SOC transfers via  
+
+q59_lutransitions_to_cropareas(i2, noncropland59) ..
+  sum((tillage59, w), v59_cropland_transitions(i2, tillage59, w, noncropland59)) =e=
+                          sum(cell(i2,j2), vm_lu_transitions(j2, noncropland59, "crop"));
+
+*' The previous SOC state on non-cropland after accounting for land-use transition is not 
+*' tillage- and irrgations-type-specific and thus given by
+
+q59_previousstate_term_noncrop(i2, noncropland59, sPools59) ..
+  v59_topsoilc_noncrop_previousstate(i2, noncropland59, sPools59)
+    =e= sum((ct, land_from), p59_topsoilc_density_pre(ct, i2, land_from, sPools59) *
+            sum(cell(i2, j2), vm_lu_transitions(j2, land_from, noncropland59)));
+ 
+*' Following the 2019-Refinement of the IPCC guidelines 2006 for cropland the actual state
+*' can be calculated via
+
+q59_actualstate_crop(i2, sPools59) ..
+               v59_topsoilc_actualstate(i2, "crop", sPools59)
+               =e= sum((tillage59, w), v59_topsoilc_crop_previousstate(i2, sPools59, w, tillage59) * 
+                        (1 - pc59_topsoilc_decay_timestep(i2, sPools59, w, tillage59))) +
+                   sum((tillage59, w), v59_topsoilc_crop_steadystate(i2, sPools59, w, tillage59) *
+                        pc59_topsoilc_decay_timestep(i2, sPools59, w, tillage59))
+               ;
+
+*' for cropland and via
+               
+q59_actualstate_noncrop(i2, noncropland59, sPools59) ..
+               v59_topsoilc_actualstate(i2, noncropland59, sPools59)
+               =e= v59_topsoilc_noncrop_previousstate(i2, noncropland59, sPools59) *
+                        (1 - pc59_topsoilc_decay_timestep(i2, sPools59, "rainfed", "notill")) +
+                   v59_topsoilc_noncrop_steadystate(i2, noncropland59, sPools59) *
+                        pc59_topsoilc_decay_timestep(i2, sPools59, "rainfed", "notill")
+              ;
+
+*' for non-cropland.
+
+*' The soil carbon content of the whole soil profile is than calculated as sum of actual topsoil pool
+*' and the reference soil carbon pool of the subsoil, that is assumed to be unaffected by human management:
+
+q59_carbon_soil(i2, land, stockType) ..
+                sum(cell(i2,j2), vm_carbon_stock(j2, land, "soilc", stockType))
+                =e= sum(sPools59, v59_topsoilc_actualstate(i2, land, sPools59)) + 
+                    sum(cell(i2,j2), vm_land(j2, land) * sum(ct, i59_subsoilc_density(ct, j2)));
+
+*' Note, that as long as the three pool soil model is on regional scale, cluster scale soil carbon stocks 
+*' are not meaningful.
+
+*' The annual nitrogen release (or sink) for cropland soils is than 
+*' calculated by the loss of soil organic carbon given by
+
+q59_nr_som(i2) ..
+             vm_nr_som(i2)
+               =e= 1/m_timestep_length_forestry * 1/15 * sum((tillage59, w, sPools59), 
+                        (v59_topsoilc_crop_previousstate(i2, sPools59, w, tillage59) -
+                         v59_topsoilc_crop_steadystate(i2, sPools59, w, tillage59))
+                        * pc59_topsoilc_decay_timestep(i2, sPools59, w, tillage59))
+              ;
+
+*' with the carbon to nitrogen ratio of soils assumed to be 15:1.
+
+*' The amount of nitrogen that becomes available to cropland farming is 
+*' limited by loss of soil organic matter by
+
+q59_nr_som_fertilizer(i2) ..
+          vm_nr_som_fertilizer(i2)
+          =l=
+          vm_nr_som(i2);
+
+*' as well as by the amount that crops can take up
+
+q59_nr_som_fertilizer2(i2) ..
+          vm_nr_som_fertilizer(i2)
+          =l=
+          sum(cell(i2,j2), vm_landexpansion(j2,"crop")) * s59_nitrogen_uptake;
+
+*' Here we assume a maximum of 200 kg on the expanded area.
diff --git a/modules/59_som/threepool_reg_may23/input.gms b/modules/59_som/threepool_reg_may23/input.gms
new file mode 100644
index 0000000000..03387987b8
--- /dev/null
+++ b/modules/59_som/threepool_reg_may23/input.gms
@@ -0,0 +1,82 @@
+*** |  (C) 2008-2023 Potsdam Institute for Climate Impact Research (PIK)
+*** |  authors, and contributors see CITATION.cff file. This file is part
+*** |  of MAgPIE and licensed under AGPL-3.0-or-later. Under Section 7 of
+*** |  AGPL-3.0, you are granted additional permissions described in the
+*** |  MAgPIE License Exception, version 1.0 (see LICENSE file).
+*** |  Contact: magpie@pik-potsdam.de
+
+scalars
+  s59_nitrogen_uptake  Maximum plant available nitrogen from soil organic matter loss (tN per ha)        / 0.2 /
+;
+
+$setglobal c59_som_scenario  cc
+*   options:  cc        (climate change)
+*             nocc      (no climate change)
+*             nocc_hist (no climate change after year defined by sm_fix_cc)
+
+parameters f59_topsoilc_density(t_all,j) LPJ topsoil carbon density for natural vegetation (tC per ha)
+/
+$ondelim
+$include "./modules/59_som/input/lpj_carbon_topsoil.cs2b"
+$offdelim
+/
+;
+$if "%c59_som_scenario%" == "nocc" f59_topsoilc_density(t_all,j) = f59_topsoilc_density("y1995",j);
+$if "%c59_som_scenario%" == "nocc_hist" f59_topsoilc_density(t_all,j)$(m_year(t_all) > sm_fix_cc) = f59_topsoilc_density(t_all,j)$(m_year(t_ai) = sm_fix_cc);
+m_fillmissingyears(f59_topsoilc_density,"j");
+
+
+table f59_cinput_multiplier_residue(i,sPools59,kcr,tillage59) LPJ topsoil carbon density for natural vegetation (tC per ha)
+$ondelim
+$include "./modules/59_som/threepool_reg_may23/input/f59_cinput_multiplier_residue.cs3"
+$offdelim
+;
+
+table f59_cinput_multiplier_manure(i,sPools59,kli,tillage59) LPJ topsoil carbon density for natural vegetation (tC per ha)
+$ondelim
+$include "./modules/59_som/threepool_reg_may23/input/f59_cinput_multiplier_manure.cs3"
+$offdelim
+;
+
+
+table f59_litter_input(t_all,i,sPools59) LPJ topsoil carbon density for natural vegetation (tC per ha)
+$ondelim
+$include "./modules/59_som/threepool_reg_may23/input/f59_litter_input.cs3"
+$offdelim
+;
+$if "%c59_som_scenario%" == "nocc" 
+  f59_litter_input(t_all,i,sPools59) = f59_litter_input("y1995",i,sPools59);
+$if "%c59_som_scenario%" == "nocc_hist" 
+  f59_litter_input(t_all,i,sPools59)$(m_year(t_all) > sm_fix_cc) = f59_litter_input(t_all,i,sPools59)$(m_year(t_ai) = sm_fix_cc);
+m_fillmissingyears(f59_litter_input,"i,sPools59");
+
+
+table f59_topsoilc_decay(t_all,i,sPools59,w,tillage59) Soil decay rates for all SOC sub-pools per year (1)
+$ondelim
+$include "./modules/59_som/threepool_reg_may23/input/f59_topsoilc_decay.cs3"
+$offdelim
+;
+$if "%c59_som_scenario%" == "nocc" 
+  f59_topsoilc_decay(t_all,i,sPools59,w,tillage59) = f59_topsoilc_decay("y1995",i,sPools59,w,tillage59);
+$if "%c59_som_scenario%" == "nocc_hist" 
+  f59_topsoilc_decay(t_all,i,sPools59,w,tillage59)$(m_year(t_all) > sm_fix_cc) = f59_topsoilc_decay(t_all,i,sPools59,w,tillage59)$(m_year(t_ai) = sm_fix_cc);
+m_fillmissingyears(f59_topsoilc_decay,"i,sPools59,w,tillage59");
+
+
+table f59_topsoilc_actualstate(i,sPools59,lutypes59) LPJ topsoil carbon for different pools and lu types(million tC)
+$ondelim 
+$include "./modules/59_som/threepool_reg_may23/input/f59_topsoilc_actualstate.cs3"
+$offdelim
+;
+
+table f59_topsoilc_naturalstate(i,sPools59,lutypes59) LPJ natural topsoil carbon for different pools and lu types(million tC)
+$ondelim
+$include "./modules/59_som/threepool_reg_may23/input/f59_topsoilc_naturalstate.cs3"
+$offdelim
+;
+
+table f59_land_y1990(t_pre59,i,land) land use in y1990 (million ha)
+$ondelim
+$include "./modules/59_som/threepool_reg_may23/input/f59_land_y1990.cs3"
+$offdelim
+;
diff --git a/modules/59_som/threepool_reg_may23/input/files b/modules/59_som/threepool_reg_may23/input/files
new file mode 100644
index 0000000000..683cbbe074
--- /dev/null
+++ b/modules/59_som/threepool_reg_may23/input/files
@@ -0,0 +1,8 @@
+* list of files that are required here
+f59_land_y1990.cs3
+f59_cinput_multiplier_residue.cs3
+f59_cinput_multiplier_manure.cs3
+f59_litter_input.cs3
+f59_topsoilc_decay.cs3
+f59_topsoilc_actualstate.cs3
+f59_topsoilc_naturalstate.cs3
diff --git a/modules/59_som/threepool_reg_may23/not_used.txt b/modules/59_som/threepool_reg_may23/not_used.txt
new file mode 100644
index 0000000000..1d37eb479c
--- /dev/null
+++ b/modules/59_som/threepool_reg_may23/not_used.txt
@@ -0,0 +1,7 @@
+name,type,reason
+fm_croparea,input,questionnaire
+pm_climate_class,input,questionnaire
+vm_fallow,input,questionnaire
+vm_treecover,input,not_used
+vm_land_other,input,not_used
+pm_avl_cropland_iso,input,nou_used
diff --git a/modules/59_som/threepool_reg_may23/postsolve.gms b/modules/59_som/threepool_reg_may23/postsolve.gms
new file mode 100644
index 0000000000..320f2227ae
--- /dev/null
+++ b/modules/59_som/threepool_reg_may23/postsolve.gms
@@ -0,0 +1,111 @@
+*** |  (C) 2008-2023 Potsdam Institute for Climate Impact Research (PIK)
+*** |  authors, and contributors see CITATION.cff file. This file is part
+*** |  of MAgPIE and licensed under AGPL-3.0-or-later. Under Section 7 of
+*** |  AGPL-3.0, you are granted additional permissions described in the
+*** |  MAgPIE License Exception, version 1.0 (see LICENSE file).
+*** |  Contact: magpie@pik-potsdam.de
+
+p59_topsoilc_actualstate(i, land, sPools59) = v59_topsoilc_actualstate.l(i, land, sPools59);
+p59_topsoilc_density_post(t, i, land, sPools59)$(sum(cell(i,j), pcm_land(j,land)) > 1e-10) = 
+  p59_topsoilc_actualstate(i, land, sPools59) / sum(cell(i,j), pcm_land(j,land));
+p59_land_before(j,land) = vm_land.l(j,land);
+
+**** natural stock calculations
+
+pc59_topsoilc_natural_steadystate(i, land, sPools59) =
+     f59_litter_input(t, i, sPools59) /
+       f59_topsoilc_decay(t, i, sPools59, "rainfed", "notill") *
+         sum(cell(i,j), vm_land.l(j, land));
+
+p59_topsoilc_naturalstate(t, i, land, sPools59)  = 
+     pc59_topsoilc_naturalstate_previous(i, land, sPools59) *
+       (1 - pc59_topsoilc_decay_timestep(i, sPools59, "rainfed", "notill")) +
+         pc59_topsoilc_natural_steadystate(i, land, sPools59) *
+           pc59_topsoilc_decay_timestep(i, sPools59, "rainfed", "notill");
+
+
+pc59_topsoilc_naturalstate_previous(i, land, sPools59) =
+  p59_topsoilc_naturalstate(t, i, land, sPools59);
+
+*#################### R SECTION START (OUTPUT DEFINITIONS) #####################
+ ov59_topsoilc_crop_steadystate(t,i,sPools59,w,tillage59,"marginal")        = v59_topsoilc_crop_steadystate.m(i,sPools59,w,tillage59);
+ ov59_topsoilc_noncrop_steadystate(t,i,noncropland59,sPools59,"marginal")   = v59_topsoilc_noncrop_steadystate.m(i,noncropland59,sPools59);
+ ov59_topsoilc_crop_previousstate(t,i,sPools59,w,tillage59,"marginal")      = v59_topsoilc_crop_previousstate.m(i,sPools59,w,tillage59);
+ ov59_cropland_transitions(t,i,tillage59,w,noncropland59,"marginal")        = v59_cropland_transitions.m(i,tillage59,w,noncropland59);
+ ov59_topsoilc_noncrop_previousstate(t,i,noncropland59,sPools59,"marginal") = v59_topsoilc_noncrop_previousstate.m(i,noncropland59,sPools59);
+ ov59_topsoilc_actualstate(t,i,land,sPools59,"marginal")                    = v59_topsoilc_actualstate.m(i,land,sPools59);
+ ov_cost_scm(t,j,"marginal")                                                = vm_cost_scm.m(j);
+ ov_nr_som(t,i,"marginal")                                                  = vm_nr_som.m(i);
+ ov_nr_som_fertilizer(t,i,"marginal")                                       = vm_nr_som_fertilizer.m(i);
+ oq59_steadystate_term_crop(t,i,sPools59,w,tillage59,"marginal")            = q59_steadystate_term_crop.m(i,sPools59,w,tillage59);
+ oq59_previousstate_term_crop(t,i,sPools59,w,tillage59,"marginal")          = q59_previousstate_term_crop.m(i,sPools59,w,tillage59);
+ oq59_lutransitions_to_cropareas(t,i,noncropland59,"marginal")              = q59_lutransitions_to_cropareas.m(i,noncropland59);
+ oq59_actualstate_crop(t,i,sPools59,"marginal")                             = q59_actualstate_crop.m(i,sPools59);
+ oq59_steadystate_term_noncrop(t,i,noncropland59,sPools59,"marginal")       = q59_steadystate_term_noncrop.m(i,noncropland59,sPools59);
+ oq59_previousstate_term_noncrop(t,i,noncropland59,sPools59,"marginal")     = q59_previousstate_term_noncrop.m(i,noncropland59,sPools59);
+ oq59_actualstate_noncrop(t,i,noncropland59,sPools59,"marginal")            = q59_actualstate_noncrop.m(i,noncropland59,sPools59);
+ oq59_carbon_soil(t,i,land,stockType,"marginal")                            = q59_carbon_soil.m(i,land,stockType);
+ oq59_nr_som(t,i,"marginal")                                                = q59_nr_som.m(i);
+ oq59_nr_som_fertilizer2(t,i,"marginal")                                    = q59_nr_som_fertilizer2.m(i);
+ oq59_nr_som_fertilizer(t,i,"marginal")                                     = q59_nr_som_fertilizer.m(i);
+ ov59_topsoilc_crop_steadystate(t,i,sPools59,w,tillage59,"level")           = v59_topsoilc_crop_steadystate.l(i,sPools59,w,tillage59);
+ ov59_topsoilc_noncrop_steadystate(t,i,noncropland59,sPools59,"level")      = v59_topsoilc_noncrop_steadystate.l(i,noncropland59,sPools59);
+ ov59_topsoilc_crop_previousstate(t,i,sPools59,w,tillage59,"level")         = v59_topsoilc_crop_previousstate.l(i,sPools59,w,tillage59);
+ ov59_cropland_transitions(t,i,tillage59,w,noncropland59,"level")           = v59_cropland_transitions.l(i,tillage59,w,noncropland59);
+ ov59_topsoilc_noncrop_previousstate(t,i,noncropland59,sPools59,"level")    = v59_topsoilc_noncrop_previousstate.l(i,noncropland59,sPools59);
+ ov59_topsoilc_actualstate(t,i,land,sPools59,"level")                       = v59_topsoilc_actualstate.l(i,land,sPools59);
+ ov_cost_scm(t,j,"level")                                                   = vm_cost_scm.l(j);
+ ov_nr_som(t,i,"level")                                                     = vm_nr_som.l(i);
+ ov_nr_som_fertilizer(t,i,"level")                                          = vm_nr_som_fertilizer.l(i);
+ oq59_steadystate_term_crop(t,i,sPools59,w,tillage59,"level")               = q59_steadystate_term_crop.l(i,sPools59,w,tillage59);
+ oq59_previousstate_term_crop(t,i,sPools59,w,tillage59,"level")             = q59_previousstate_term_crop.l(i,sPools59,w,tillage59);
+ oq59_lutransitions_to_cropareas(t,i,noncropland59,"level")                 = q59_lutransitions_to_cropareas.l(i,noncropland59);
+ oq59_actualstate_crop(t,i,sPools59,"level")                                = q59_actualstate_crop.l(i,sPools59);
+ oq59_steadystate_term_noncrop(t,i,noncropland59,sPools59,"level")          = q59_steadystate_term_noncrop.l(i,noncropland59,sPools59);
+ oq59_previousstate_term_noncrop(t,i,noncropland59,sPools59,"level")        = q59_previousstate_term_noncrop.l(i,noncropland59,sPools59);
+ oq59_actualstate_noncrop(t,i,noncropland59,sPools59,"level")               = q59_actualstate_noncrop.l(i,noncropland59,sPools59);
+ oq59_carbon_soil(t,i,land,stockType,"level")                               = q59_carbon_soil.l(i,land,stockType);
+ oq59_nr_som(t,i,"level")                                                   = q59_nr_som.l(i);
+ oq59_nr_som_fertilizer2(t,i,"level")                                       = q59_nr_som_fertilizer2.l(i);
+ oq59_nr_som_fertilizer(t,i,"level")                                        = q59_nr_som_fertilizer.l(i);
+ ov59_topsoilc_crop_steadystate(t,i,sPools59,w,tillage59,"upper")           = v59_topsoilc_crop_steadystate.up(i,sPools59,w,tillage59);
+ ov59_topsoilc_noncrop_steadystate(t,i,noncropland59,sPools59,"upper")      = v59_topsoilc_noncrop_steadystate.up(i,noncropland59,sPools59);
+ ov59_topsoilc_crop_previousstate(t,i,sPools59,w,tillage59,"upper")         = v59_topsoilc_crop_previousstate.up(i,sPools59,w,tillage59);
+ ov59_cropland_transitions(t,i,tillage59,w,noncropland59,"upper")           = v59_cropland_transitions.up(i,tillage59,w,noncropland59);
+ ov59_topsoilc_noncrop_previousstate(t,i,noncropland59,sPools59,"upper")    = v59_topsoilc_noncrop_previousstate.up(i,noncropland59,sPools59);
+ ov59_topsoilc_actualstate(t,i,land,sPools59,"upper")                       = v59_topsoilc_actualstate.up(i,land,sPools59);
+ ov_cost_scm(t,j,"upper")                                                   = vm_cost_scm.up(j);
+ ov_nr_som(t,i,"upper")                                                     = vm_nr_som.up(i);
+ ov_nr_som_fertilizer(t,i,"upper")                                          = vm_nr_som_fertilizer.up(i);
+ oq59_steadystate_term_crop(t,i,sPools59,w,tillage59,"upper")               = q59_steadystate_term_crop.up(i,sPools59,w,tillage59);
+ oq59_previousstate_term_crop(t,i,sPools59,w,tillage59,"upper")             = q59_previousstate_term_crop.up(i,sPools59,w,tillage59);
+ oq59_lutransitions_to_cropareas(t,i,noncropland59,"upper")                 = q59_lutransitions_to_cropareas.up(i,noncropland59);
+ oq59_actualstate_crop(t,i,sPools59,"upper")                                = q59_actualstate_crop.up(i,sPools59);
+ oq59_steadystate_term_noncrop(t,i,noncropland59,sPools59,"upper")          = q59_steadystate_term_noncrop.up(i,noncropland59,sPools59);
+ oq59_previousstate_term_noncrop(t,i,noncropland59,sPools59,"upper")        = q59_previousstate_term_noncrop.up(i,noncropland59,sPools59);
+ oq59_actualstate_noncrop(t,i,noncropland59,sPools59,"upper")               = q59_actualstate_noncrop.up(i,noncropland59,sPools59);
+ oq59_carbon_soil(t,i,land,stockType,"upper")                               = q59_carbon_soil.up(i,land,stockType);
+ oq59_nr_som(t,i,"upper")                                                   = q59_nr_som.up(i);
+ oq59_nr_som_fertilizer2(t,i,"upper")                                       = q59_nr_som_fertilizer2.up(i);
+ oq59_nr_som_fertilizer(t,i,"upper")                                        = q59_nr_som_fertilizer.up(i);
+ ov59_topsoilc_crop_steadystate(t,i,sPools59,w,tillage59,"lower")           = v59_topsoilc_crop_steadystate.lo(i,sPools59,w,tillage59);
+ ov59_topsoilc_noncrop_steadystate(t,i,noncropland59,sPools59,"lower")      = v59_topsoilc_noncrop_steadystate.lo(i,noncropland59,sPools59);
+ ov59_topsoilc_crop_previousstate(t,i,sPools59,w,tillage59,"lower")         = v59_topsoilc_crop_previousstate.lo(i,sPools59,w,tillage59);
+ ov59_cropland_transitions(t,i,tillage59,w,noncropland59,"lower")           = v59_cropland_transitions.lo(i,tillage59,w,noncropland59);
+ ov59_topsoilc_noncrop_previousstate(t,i,noncropland59,sPools59,"lower")    = v59_topsoilc_noncrop_previousstate.lo(i,noncropland59,sPools59);
+ ov59_topsoilc_actualstate(t,i,land,sPools59,"lower")                       = v59_topsoilc_actualstate.lo(i,land,sPools59);
+ ov_cost_scm(t,j,"lower")                                                   = vm_cost_scm.lo(j);
+ ov_nr_som(t,i,"lower")                                                     = vm_nr_som.lo(i);
+ ov_nr_som_fertilizer(t,i,"lower")                                          = vm_nr_som_fertilizer.lo(i);
+ oq59_steadystate_term_crop(t,i,sPools59,w,tillage59,"lower")               = q59_steadystate_term_crop.lo(i,sPools59,w,tillage59);
+ oq59_previousstate_term_crop(t,i,sPools59,w,tillage59,"lower")             = q59_previousstate_term_crop.lo(i,sPools59,w,tillage59);
+ oq59_lutransitions_to_cropareas(t,i,noncropland59,"lower")                 = q59_lutransitions_to_cropareas.lo(i,noncropland59);
+ oq59_actualstate_crop(t,i,sPools59,"lower")                                = q59_actualstate_crop.lo(i,sPools59);
+ oq59_steadystate_term_noncrop(t,i,noncropland59,sPools59,"lower")          = q59_steadystate_term_noncrop.lo(i,noncropland59,sPools59);
+ oq59_previousstate_term_noncrop(t,i,noncropland59,sPools59,"lower")        = q59_previousstate_term_noncrop.lo(i,noncropland59,sPools59);
+ oq59_actualstate_noncrop(t,i,noncropland59,sPools59,"lower")               = q59_actualstate_noncrop.lo(i,noncropland59,sPools59);
+ oq59_carbon_soil(t,i,land,stockType,"lower")                               = q59_carbon_soil.lo(i,land,stockType);
+ oq59_nr_som(t,i,"lower")                                                   = q59_nr_som.lo(i);
+ oq59_nr_som_fertilizer2(t,i,"lower")                                       = q59_nr_som_fertilizer2.lo(i);
+ oq59_nr_som_fertilizer(t,i,"lower")                                        = q59_nr_som_fertilizer.lo(i);
+*##################### R SECTION END (OUTPUT DEFINITIONS) ######################
diff --git a/modules/59_som/threepool_reg_may23/preloop.gms b/modules/59_som/threepool_reg_may23/preloop.gms
new file mode 100644
index 0000000000..a4b150d808
--- /dev/null
+++ b/modules/59_som/threepool_reg_may23/preloop.gms
@@ -0,0 +1,33 @@
+*** |  (C) 2008-2023 Potsdam Institute for Climate Impact Research (PIK)
+*** |  authors, and contributors see CITATION.cff file. This file is part
+*** |  of MAgPIE and licensed under AGPL-3.0-or-later. Under Section 7 of
+*** |  AGPL-3.0, you are granted additional permissions described in the
+*** |  MAgPIE License Exception, version 1.0 (see LICENSE file).
+*** |  Contact: magpie@pik-potsdam.de
+
+
+*****************************
+*** SOC initialisation    ***
+*****************************
+
+i59_subsoilc_density(t_all, j) = 
+  fm_carbon_density(t_all, j, "secdforest", "soilc") - f59_topsoilc_density(t_all, j);
+  
+
+pcm_carbon_stock(j, land, "soilc", stockType) = 
+ fm_carbon_density("y1995", j, land, "soilc") * pm_land_start(j, land);
+
+vm_carbon_stock.l(j, land, "soilc", stockType) =
+  pcm_carbon_stock(j, land, "soilc", stockType);
+
+p59_land_before(j,land) = pm_land_start(j,land);
+
+*****************************
+*** parameter dummies     ***
+*****************************
+
+i59_cinput_multiplier_residue(i,sPools59,kcr) = 
+  sum(kcr2$(sameas(kcr,kcr2)), 
+    sum(kcr_tillage59(kcr2,tillage59), 
+      f59_cinput_multiplier_residue(i,sPools59,kcr,tillage59)));
+
diff --git a/modules/59_som/threepool_reg_may23/presolve.gms b/modules/59_som/threepool_reg_may23/presolve.gms
new file mode 100644
index 0000000000..0222b349e4
--- /dev/null
+++ b/modules/59_som/threepool_reg_may23/presolve.gms
@@ -0,0 +1,65 @@
+*** |  (C) 2008-2023 Potsdam Institute for Climate Impact Research (PIK)
+*** |  authors, and contributors see CITATION.cff file. This file is part
+*** |  of MAgPIE and licensed under AGPL-3.0-or-later. Under Section 7 of
+*** |  AGPL-3.0, you are granted additional permissions described in the
+*** |  MAgPIE License Exception, version 1.0 (see LICENSE file).
+*** |  Contact: magpie@pik-potsdam.de
+
+vm_cost_scm.fx(j) = 0;
+
+* For the first time steps:
+* Initializating of SOC pools in the different land types using the input from mrsoil
+
+* For all other time steps:
+* SOM pools and densities will be updated after natural regrowth and disturbance loss accounting.
+* The secondary forest pool will receive carbon from primary forest (due to natural disturbance)
+* and from other land (due to regrowth).
+* Note: This will only account for transitions of primary forest to secondary forest and
+* other land to secondary forest. See current version of 35_natveg to check consistency.
+* The helper parameter `p59_topsoilc_actualstate` is used  to update `p59_topsoilc_density_pre`
+
+i59_topsoilc_decay_max1(t, i, sPools59, w, tillage59) =
+  min(1, f59_topsoilc_decay(t, i, sPools59, w, tillage59));
+
+pc59_topsoilc_decay_timestep(i, sPools59, w, tillage59) = 
+  1 - (1 - i59_topsoilc_decay_max1(t, i, sPools59, w, tillage59)) ** m_yeardiff_forestry(t);
+
+if((ord(t) = 1),
+
+  p59_topsoilc_density_pre("y1995", i, land, sPools59) =
+    sum(lutypes59_land(land, lutypes59),
+      f59_topsoilc_actualstate(i, sPools59, lutypes59)  /
+        sum(lutypes59_land2(land2,lutypes59), f59_land_y1990("y1990", i, land2)));
+
+  p59_topsoilc_density_post(t, i, land, sPools59) = 0;
+  p59_topsoilc_actualstate(i, land, sPools59) = 0;
+
+  pc59_topsoilc_naturalstate_previous(i, land, sPools59) = 
+    sum(lutypes59_land(land, lutypes59),
+      f59_topsoilc_naturalstate(i, sPools59, lutypes59)  /
+        sum(lutypes59_land2(land2,lutypes59), f59_land_y1990("y1990", i, land2))) * 
+          f59_land_y1990("y1990", i, land);
+ 
+else
+
+  p59_topsoilc_actualstate(i, "secdforest", sPools59) = 
+    p59_topsoilc_actualstate(i, "secdforest", sPools59) + 
+    sum(cell(i,j), p59_land_before(j, "primforest") - pcm_land(j, "primforest")) *
+      p59_topsoilc_density_post(t-1, i, "primforest", sPools59) + 
+    sum(cell(i,j), p59_land_before(j, "other") - pcm_land(j, "other")) *
+      p59_topsoilc_density_post(t-1, i, "other", sPools59);
+
+  p59_topsoilc_actualstate(i, "other", sPools59) = 
+    p59_topsoilc_actualstate(i, "other", sPools59) - 
+    sum(cell(i,j), p59_land_before(j, "other") - pcm_land(j, "other")) *
+      p59_topsoilc_density_post(t-1, i, "other", sPools59);
+
+  p59_topsoilc_actualstate(i, "primforest", sPools59) = 
+    p59_topsoilc_actualstate(i, "primforest", sPools59) - 
+    sum(cell(i,j), p59_land_before(j, "primforest") - pcm_land(j, "primforest")) *
+      p59_topsoilc_density_post(t-1, i, "primforest", sPools59);
+
+  p59_topsoilc_density_pre(t, i, land, sPools59)$(sum(cell(i,j), pcm_land(j,land)) > 1e-20) =
+    p59_topsoilc_actualstate(i, land, sPools59) / sum(cell(i,j), pcm_land(j,land));
+
+);
diff --git a/modules/59_som/threepool_reg_may23/realization.gms b/modules/59_som/threepool_reg_may23/realization.gms
new file mode 100644
index 0000000000..ddea7638b1
--- /dev/null
+++ b/modules/59_som/threepool_reg_may23/realization.gms
@@ -0,0 +1,27 @@
+*** |  (C) 2008-2023 Potsdam Institute for Climate Impact Research (PIK)
+*** |  authors, and contributors see CITATION.cff file. This file is part
+*** |  of MAgPIE and licensed under AGPL-3.0-or-later. Under Section 7 of
+*** |  AGPL-3.0, you are granted additional permissions described in the
+*** |  MAgPIE License Exception, version 1.0 (see LICENSE file).
+*** |  Contact: magpie@pik-potsdam.de
+
+*' @description
+*' The threepool_may23 realization is based on the Tier 2 approach of the revised IPCC 
+*' Guidelines for National Greenhouse Gas Inventories 2019 (@calvo_buendia_ipcc_2019). 
+*' It calculates the stock of soil carbon for all land-use types based on a reduced complexity 
+*' soil model driven by carbon inputs and decay rates depending on management decisions. 
+
+*' @limitations tba
+
+*' @authors Kristine Karstens
+
+*####################### R SECTION START (PHASES) ##############################
+$Ifi "%phase%" == "sets" $include "./modules/59_som/threepool_may23/sets.gms"
+$Ifi "%phase%" == "declarations" $include "./modules/59_som/threepool_may23/declarations.gms"
+$Ifi "%phase%" == "input" $include "./modules/59_som/threepool_may23/input.gms"
+$Ifi "%phase%" == "equations" $include "./modules/59_som/threepool_may23/equations.gms"
+$Ifi "%phase%" == "scaling" $include "./modules/59_som/threepool_may23/scaling.gms"
+$Ifi "%phase%" == "preloop" $include "./modules/59_som/threepool_may23/preloop.gms"
+$Ifi "%phase%" == "presolve" $include "./modules/59_som/threepool_may23/presolve.gms"
+$Ifi "%phase%" == "postsolve" $include "./modules/59_som/threepool_may23/postsolve.gms"
+*######################## R SECTION END (PHASES) ###############################
diff --git a/modules/59_som/threepool_reg_may23/scaling.gms b/modules/59_som/threepool_reg_may23/scaling.gms
new file mode 100644
index 0000000000..0002b1eb7d
--- /dev/null
+++ b/modules/59_som/threepool_reg_may23/scaling.gms
@@ -0,0 +1,12 @@
+*** |  (C) 2008-2024 Potsdam Institute for Climate Impact Research (PIK)
+*** |  authors, and contributors see CITATION.cff file. This file is part
+*** |  of MAgPIE and licensed under AGPL-3.0-or-later. Under Section 7 of
+*** |  AGPL-3.0, you are granted additional permissions described in the
+*** |  MAgPIE License Exception, version 1.0 (see LICENSE file).
+*** |  Contact: magpie@pik-potsdam.de
+
+v59_topsoilc_crop_steadystate.scale(i,sPools59,w,tillage59) = 10e4;      
+v59_topsoilc_noncrop_steadystate.scale(i,noncropland59,sPools59) = 10e4;  
+v59_topsoilc_crop_previousstate.scale(i,sPools59,w,tillage59) = 10e4;     
+v59_topsoilc_noncrop_previousstate.scale(i,noncropland59,sPools59) = 10e4;
+v59_topsoilc_actualstate.scale(i,land,sPools59) = 10e4; 
diff --git a/modules/59_som/threepool_reg_may23/sets.gms b/modules/59_som/threepool_reg_may23/sets.gms
new file mode 100644
index 0000000000..2d9698275e
--- /dev/null
+++ b/modules/59_som/threepool_reg_may23/sets.gms
@@ -0,0 +1,63 @@
+*** |  (C) 2008-2023 Potsdam Institute for Climate Impact Research (PIK)
+*** |  authors, and contributors see CITATION.cff file. This file is part
+*** |  of MAgPIE and licensed under AGPL-3.0-or-later. Under Section 7 of
+*** |  AGPL-3.0, you are granted additional permissions described in the
+*** |  MAgPIE License Exception, version 1.0 (see LICENSE file).
+*** |  Contact: magpie@pik-potsdam.de
+
+sets
+
+t_pre59  Year of the previous time step
+       / y1990 /
+
+sPools59 soil pools
+/ active, slow, passive /
+
+noncropland59(land) Soil carbon conserving landuse types
+/ past, forestry, primforest, secdforest, other, urban /
+
+tillage59 Tillage categories of IPCC
+/ fulltill, reducedtill, notill /
+
+lutypes59 Land-use types 
+/ crop, natveg /
+
+kcr_tillage59(kcr,tillage59) Climate classification types
+           /
+           begr      .(reducedtill) "reduced tillage"
+           betr      .(reducedtill) "reduced tillage"
+           cassav_sp .(fulltill) "full tillage"
+           cottn_pro .(fulltill) "full tillage"
+           foddr     .(fulltill) "full tillage"
+           groundnut .(fulltill) "full tillage"
+           maiz      .(fulltill) "full tillage"
+           oilpalm   .(reducedtill) "reduced tillage"
+           others    .(reducedtill) "reduced tillage"
+           potato    .(fulltill) "full tillage"
+           puls_pro  .(fulltill) "full tillage"
+           rapeseed  .(fulltill) "full tillage"
+           rice_pro  .(fulltill) "full tillage"
+           soybean   .(fulltill) "full tillage"
+           sugr_beet .(fulltill) "full tillage"
+           sugr_cane .(reducedtill) "reduced tillage"
+           sunflower .(fulltill) "full tillage"
+           tece      .(fulltill) "full tillage"
+           trce      .(fulltill) "full tillage"
+           /
+
+lutypes59_land(land,lutypes59) Mapping land to soil model land classes
+           /
+           crop       .(crop)   "cropland"
+           past       .(natveg) "potential natural vegetation"
+           forestry   .(natveg) "potential natural vegetation"
+           primforest .(natveg) "potential natural vegetation"
+           secdforest .(natveg) "potential natural vegetation"
+           other      .(natveg) "potential natural vegetation"
+           urban      .(natveg) "potential natural vegetation"
+           / 
+;
+
+alias(noncropland59,noncropland59_2);
+alias(land,land2);
+alias(lutypes59_land,lutypes59_land2);
+alias(kcr,kcr2);
diff --git a/modules/80_optimization/lp_nlp_apr17/input.gms b/modules/80_optimization/lp_nlp_apr17/input.gms
index 3945d0c594..8cec7331f5 100644
--- a/modules/80_optimization/lp_nlp_apr17/input.gms
+++ b/modules/80_optimization/lp_nlp_apr17/input.gms
@@ -7,7 +7,7 @@
 
 scalars
     s80_maxiter   maximal solve iterations if modelstat is > 2 (1)      / 30 /
-    s80_optfile     switch to use specfied solver settings (1)          / 0 /
+    s80_optfile     switch to use specfied solver settings (1)          / 1 /
     s80_add_cplex   add cplex optimization after conopt4 (1)            / 0 /
     s80_add_conopt3 add conopt3 optimization after conopt4 (1)          / 0 /
     s80_secondsolve     second solve statement (binary)                 / 0 / 
diff --git a/modules/80_optimization/nlp_apr17/input.gms b/modules/80_optimization/nlp_apr17/input.gms
index 051075eec3..1486c3a2a0 100644
--- a/modules/80_optimization/nlp_apr17/input.gms
+++ b/modules/80_optimization/nlp_apr17/input.gms
@@ -7,6 +7,7 @@
 
 scalars
     s80_maxiter         maximal solve iterations if modelstat is > 2 (1)    / 30 /
-    s80_optfile         switch to use specfied solver settings (1)          / 0 /
-    s80_secondsolve     second solve statement (binary)                     / 0 / 
+    s80_optfile         switch to use specfied solver settings (1)          / 1 /
+    s80_secondsolve     second solve statement (binary)                     / 0 /
+    s80_toloptimal      value for CONOPT4 Tol_Optimality                        / 1e-08 /
 ;
diff --git a/modules/80_optimization/nlp_apr17/solve.gms b/modules/80_optimization/nlp_apr17/solve.gms
index ffdb6bfc0e..d9facfe83a 100644
--- a/modules/80_optimization/nlp_apr17/solve.gms
+++ b/modules/80_optimization/nlp_apr17/solve.gms
@@ -18,16 +18,12 @@ magpie.scaleopt  = 1 ;
 magpie.solprint  = 0 ;
 magpie.holdfixed = 1 ;
 
-$onecho > conopt4.opt
-Lim_Variable = 1.e25
-$offecho
+put optfile;
+put 'Tol_Optimality = ', s80_toloptimal:12:11 /;
+putclose optfile;
 
 $onecho > conopt4.op2
-Flg_Prep = FALSE
-$offecho
-
-$onecho > conopt4.op3
-Flg_NoDefc = TRUE
+Lim_Variable = 1.e25
 $offecho
 
 if(execerror > 0, 
@@ -62,14 +58,10 @@ if (magpie.modelstat > 2,
       option nlp = conopt4;
       magpie.optfile = 1;
     elseif s80_resolve_option = 3,
-      display "Modelstat > 2 | Retry solve with CONOPT4 w/o preprocessing";
+      display "Modelstat > 2 | Retry solve with CONOPT4 increasing largest allowable value";
       option nlp = conopt4;
       magpie.optfile = 2;
     elseif s80_resolve_option = 4,
-      display "Modelstat > 2 | Retry solve with CONOPT4 w/o search for definitional constraints";
-      option nlp = conopt4;
-      magpie.optfile = 3;
-    elseif s80_resolve_option = 5,
       display "Modelstat > 2 | Retry solve with CONOPT3";
       option nlp = conopt3;
       magpie.optfile = 0;
@@ -94,7 +86,7 @@ if (magpie.modelstat > 2,
 *   Otherwise, the repeat loop will never end.
     magpie.modelStat$(magpie.modelStat=NA) = 13;
 
-    s80_resolve_option$(s80_resolve_option >= 5) = 0;
+    s80_resolve_option$(s80_resolve_option >= 4) = 0;
 
     until (magpie.modelstat <= 2 or s80_counter >= s80_maxiter)
   );
diff --git a/modules/80_optimization/nlp_par/input.gms b/modules/80_optimization/nlp_par/input.gms
index 39891d8b17..f3fbe6695c 100644
--- a/modules/80_optimization/nlp_par/input.gms
+++ b/modules/80_optimization/nlp_par/input.gms
@@ -7,6 +7,6 @@
 
 scalars
     s80_maxiter         maximal solve iterations if modelstat is > 2 (1)  / 30 /
-    s80_optfile         switch to use specfied solver settings (1)        / 0 /
+    s80_optfile         switch to use specfied solver settings (1)        / 1 /
     s80_secondsolve     second solve statement (binary)                   / 0 / 
 ;
diff --git a/scripts/start/compilation_check.R b/scripts/start/compilation_check.R
index bdf61a0633..b6b20e5de8 100644
--- a/scripts/start/compilation_check.R
+++ b/scripts/start/compilation_check.R
@@ -14,5 +14,11 @@ source("scripts/start_functions.R")
 source("config/default.cfg")
 download_and_update(cfg)
 
+# update all parameters which contain the levels and marginals
+# of all variables and equations
+gms::update_fulldataOutput()
+# Update module paths in GAMS code
+gms::update_modules_embedding()
+
 # compile main.gms
 system("gams main.gms action=c")
diff --git a/scripts/start/extra/soc-test.R b/scripts/start/extra/soc-test.R
new file mode 100644
index 0000000000..c2ed7c28f6
--- /dev/null
+++ b/scripts/start/extra/soc-test.R
@@ -0,0 +1,135 @@
+# |  (C) 2008-2023 Potsdam Institute for Climate Impact Research (PIK)
+# |  authors, and contributors see CITATION.cff file. This file is part
+# |  of MAgPIE and licensed under AGPL-3.0-or-later. Under Section 7 of
+# |  AGPL-3.0, you are granted additional permissions described in the
+# |  MAgPIE License Exception, version 1.0 (see LICENSE file).
+# |  Contact: magpie@pik-potsdam.de
+
+# ----------------------------------------------------------
+# description: Test SOC und residues
+# ----------------------------------------------------------
+
+
+######################################
+#### Script to start a MAgPIE run ####
+######################################
+
+## Load lucode2 and gms to use setScenario later
+library(lucode2)
+library(gms)
+library(magclass)
+
+# Load start_run(cfg) function which is needed to start MAgPIE runs
+source("scripts/start_functions.R")
+
+# Source default cfg. This loads the object "cfg" in R environment
+source("config/default.cfg")
+
+
+### THREEPOOL SOM ###
+cfg$gms$som <- "threepool_may23"
+
+cfg$title <- "default3p_disAgg"
+start_run(cfg)
+
+cfg$title <- "default3p_disAgg_off"
+cfg$gms$disagg_lvst <- "off"
+start_run(cfg)
+
+cfg$title <- "default3p_disAgg_old"
+cfg$gms$disagg_lvst <- "foragebased_aug18"
+start_run(cfg)
+cfg$gms$disagg_lvst <- "foragebased_jul23"
+
+cfg$gms$nitrogen    <- "off" 
+cfg$title <- "default3p_nitrogen_off"
+start_run(cfg)
+cfg$gms$nitrogen    <- "rescaled_jan21" 
+
+cfg$gms$methane  <- "off" 
+cfg$title <- "default3p_methane_off"
+start_run(cfg)
+cfg$gms$methane  <- "ipcc2006_aug22" 
+
+cfg$gms$awms  <- "off" 
+cfg$title <- "default3p_awms_off"
+start_run(cfg)
+cfg$gms$awms  <- "ipcc2006_aug16" 
+
+cfg$gms$c32_aff_policy <- "none" 
+cfg$gms$c35_aolc_policy <- "none"
+cfg$gms$c56_pollutant_prices <- "none"
+cfg$title <- "default3p_npi_off"
+start_run(cfg)
+
+
+### STATIC SOM ###
+cfg$gms$som <- "static_jan19"
+
+cfg$title <- "default_disAgg"
+start_run(cfg)
+
+cfg$title <- "default_disAgg_off"
+cfg$gms$disagg_lvst <- "off"
+start_run(cfg)
+
+cfg$title <- "default_disAgg_old"
+cfg$gms$disagg_lvst <- "foragebased_aug18"
+start_run(cfg)
+cfg$gms$disagg_lvst <- "foragebased_jul23"
+
+cfg$gms$nitrogen    <- "off"           
+cfg$title <- "default_nitrogen_off"
+start_run(cfg)
+cfg$gms$nitrogen    <- "rescaled_jan21"
+
+cfg$gms$methane  <- "off"           
+cfg$title <- "default_methane_off"
+start_run(cfg)
+cfg$gms$methane  <- "ipcc2006_aug22"
+
+cfg$gms$awms  <- "off"           
+cfg$title <- "default_awms_off"
+start_run(cfg)
+cfg$gms$awms  <- "ipcc2006_aug16"
+
+cfg$gms$c32_aff_policy <- "none"
+cfg$gms$c35_aolc_policy <- "none"
+cfg$gms$c56_pollutant_prices <- "none"             
+cfg$title <- "default_npi_off"
+start_run(cfg)
+
+
+ 
+#cfg <- setScenario(cfg,c("SSP2","NPI"))
+#cfg$gms$c56_mute_ghgprices_until <- "y2150"
+#cfg$gms$c56_pollutant_prices <- paste0("R21M42-SSP2-NPi")
+#cfg$gms$c60_2ndgen_biodem    <- paste0("R21M42-SSP2-NPi")
+
+#cfg$gms$som <- "threepool_may23" 
+#cfg$title <- "SSP2-REF-threepool"
+#start_run(cfg, codeCheck = FALSE)
+
+#cfg <- setScenario(cfg,c("SSP2","NDC"))
+#cfg$gms$c56_mute_ghgprices_until <- "y2030"
+#cfg$gms$c56_pollutant_prices <- paste0("R21M42-SSP2-PkBudg900")
+#cfg$gms$c60_2ndgen_biodem    <- paste0("R21M42-SSP2-PkBudg900")
+
+#cfg$gms$som <- "threepool_may23" 
+#cfg$title <- "SSP2-PkBudg900-threepool"
+#start_run(cfg, codeCheck = FALSE)
+
+#cfg$s60_scale_res2ndgenBE <- 0
+#cfg$gms$som <- "threepool_may23"
+#cfg$title <- "SSP2-PkBudg900-threepool_0x2ndRes"
+#start_run(cfg, codeCheck = FALSE)
+
+#cfg$s60_scale_res2ndgenBE <- 2
+#cfg$gms$som <- "threepool_may23"
+#cfg$title <- "SSP2-PkBudg900-threepool_2x2ndRe"
+#start_run(cfg, codeCheck = FALSE)
+
+#cfg$s60_scale_res2ndgenBE <- 5
+#cfg$gms$som <- "threepool_may23"
+#cfg$title <- "SSP2-PkBudg900-threepool_5x2ndRe"
+#start_run(cfg, codeCheck = FALSE)