SoilGen2 model: data requirements and model output 1. Essential plot data... 1 2. Essential soil data... 2 3. Precipitation data (for a typical year)... 2 4. Evapotranspiration and Air temperature data (for a typical year)... 2 5. Climate and vegetation data (timeseries)... 2 6. Weathering rates and initial cation pools locked in primary minerals... 2 7. Chemical equilibrium constants and activation energy... 3 8. Timing for C-inputs per vegetation type in a typical year... 3 9. History of atmospheric pco2-levels (time series)... 4 10. Bioturbation history as intensity with depth (time series)... 4 11. Fertilization history (time series)... 4 12. Event history... 4 13. Process constants... 4 14. Model outputs... 4 The below table links the data categories 1..13 to files. The yellow-marked data groups are the most essential to be able to run SoilGen in a local context. group (numbers refer to list below) File m/v 1. Essential plot data Input via user interface or <SoilGenBatch.txt> M 2. Essential soil data 3. Precipitation data for typical year Soil input file coupled via user interface or <SoilGenBatch.txt> M 4. Evapotranspiration and Air temperature data for a typical year 5. Climate and vegetation data (time series) File coupled via user interface (default: <climate.txt> ) V 6. Initial status minerals File coupled via user interface or <SoilGenBatch.txt> M 7. Chemical equilibrium constants and activation energy File coupled via user interface or <SoilGenBatch.txt> M 8. Timing for C-inputs per vegetation type in a typical year File coupled via user interface or <SoilGenBatch.txt> M 9. Atmospheric pco 2-levels (time series) File coupled via user interface V 10. Bioturbation intensity with depth (time series) File coupled via user interface (default: <BioturbINT.txt> ) V 11. Fertilization data (time series) File coupled via user interface (default: <Fertilization.txt> ) V 12. Event data (erosion, deposition, water table, change in hydraulic File coupled via user interface (default: <Events.txt> ) V characteristics, plowing, SlashBurn) 13. Various process constants File modifiable via user interface (default: <SoftConstants.txt> ) V M=mandatory file; V=not mandatory Detailed information can be found in the user guide at http://users.ugent.be/~pfinke/index_bestanden/soilgen%20user%20manual.pdf 1. Essential plot data Slope angle (degrees) Upslope bearing (degrees) Downwind bearing (degrees) Latitude (degrees) 1
2. Essential soil data Per soil layer: Starting depth Ending depth cm Initial Clay% Initial Silt% Initial Sand% Initial OC% Mass% solid fraction, should sum to 100% Initial Bulk density kg dm -3 Initial moisture content dm 3 dm -3 Initial temperature C Initial calcite content Initial gypsum content Mass fraction mineral phase Initial pco 2 bar Initial CEC ol + kg -1 Mg/Ca Ca/Na Ca/K Ca/Al Ca/H Selectivity Coefficients Initial amounts in solution Ca, Mg, K, Na, Al Cl, SO4, Alkalinity ol dm 3 Initial amount at exchange complex Ca, Mg, K, Na, H, Al ol + kg -1 3. Precipitation data (for a typical year) Per Julian day Fraction of day where precipitation starts Amount of precipitation Surface flux density d -1 Water composition Ca, Mg, Na, K, Cl, SO4, Alkalinity, Al ol dm -3 4. Evapotranspiration and Air temperature data (for a typical year) Per week Potential evapotranspiration (sum for the week) Mean daily temperature C (calculated over the week) Mean daily amplitude C (calculated over the week) 5. Climate and vegetation data (timeseries) For specific years along the timeline (missing values will be interpolated) YearBP P EP JanT JulT PlantsInC(t/ha,y) ManureInC(t/ha,y) Vegetation Period Annual precipitation Annual potential evapotranspiration Average January temperature C Average July temperature C Annual C-input (root and leaf litter or crop residue) of plants kg.1000 ha -1 y -1 Annual C-input as organic manure (SoilGen2.25+: NPP can be estimated in user interface) kg.1000 ha -1 y -1 Vegetation type (4 types possible) 6. Weathering rates and initial cation pools locked in primary minerals SoilGen2.24: the profile is assumed to be homogeneous for primary minerals! Weathering rate Ca from primary minerals m 3 mol -1 c y -1 Weathering rate Mg from primary minerals m 3 mol -1 c y -1 Weathering rate K from primary minerals m 3 mol -1 c y -1 Weathering rate Na from primary minerals m 3 mol -1 c y -1 2
coefficient for congruent weathering Anorthite (Ca) with respect to Al - coefficient for congruent weathering Chlorite (Mg) with respect to Al - coefficient for congruent weathering Microcline (K) with respect to Al - coefficient for congruent weathering Albite (Na) with respect to Al - Initial free" Al; initial Gibsite pool) Initial Ca (e.g. from total analysis corrected for Ca not in primary silicate minerals) Initial Mg (e.g. from total analysis corrected for Mg not in primary silicate minerals) Initial K (e.g. from total analysis corrected for K not in primary silicate minerals) Initial Na (e.g. from total analysis corrected for Na not in primary silicate minerals) SoilGen2.25 and later: (per layer) Units Albite (NaAlSi3O8) K-feldspar (KAlSi3O8) Muscovite (KAl3Si3O10(OH)2) Biotite (KMg1.5Fe1.5AlSi3O10(OH)2) Quartz (SiO2) Chlorite As Clinochlore (Mg5Al2Si3O10 (OH)8) Anorthite (CaAl2Si2O8) Fosterite (Mg2SiO4) Augite As Orthoferrosilite (FeSiO3) Kaolinite (Al2Si2O5(OH)4) Illite (Si3.4O10(OH)2Mg0.02Al2.38Ca0.01K0.44) Montmorillonite (Si4O10(OH)2Mg0.33Al1.67Ca0.04125Mg0.04125K0.0825Na0.0825) Hornblende (Ca2Mg4AlSi6.7AlO22.4) Fayalite (Fe2SiO4) Gibbsite (Al(OH)3) Amorphite (mineral with input composition in Amorphite.txt) massfraction Otherite (mineral with input composition in Otherite.txt) massfraction 7. Chemical equilibrium constants and activation energy Henrys law constant for CO2 at 25 C and activation energy - and kj mol -1 Stability constant of water at 25 C and activation energy - and kj mol -1 First dissociation constant of H2CO3 at 25 C and activation energy - and kj mol -1 Second dissociation constant of H2CO3 at 25 C and activation energy - and kj mol -1 Stability constant of CaCO3 at 25 C and activation energy - and kj mol -1 Stability constant of CaHCO3+ at 25 C and activation energy - and kj mol -1 Stability constant of CaOH+ at 25 C and activation energy - and kj mol -1 Stability constant of CaSO4 at 25 C and activation energy - and kj mol -1 Stability constant of MgCO3 at 25 C and activation energy - and kj mol -1 Stability constant of MgHCO3+ at 25 C and activation energy - and kj mol -1 Stability constant of MgOH+ at 25 C and activation energy - and kj mol -1 Stability constant of MgSO4 at 25 C and activation energy - and kj mol -1 Stability constant of NaSO4- at 25 C and activation energy - and kj mol -1 Stability constant of NaCO3- at 25 C and activation energy - and kj mol -1 Stability constant of KSO4- at 25 C and activation energy - and kj mol -1 Solubility product of gypsum at 25 C and activation energy - and kj mol -1 Solubility product of calcite at 25 C and activation energy - and kj mol -1 Solubility product of Gibbsite at 25 C and activation energy - and kj mol -1 8. Timing for C-inputs per vegetation type in a typical year initial profile data: distribution C over various pools (%) (all soil compartments) % Per month in a typical year for each one of 4 vegetation types: Percentage of the plant residues (litter) input to the soil % Percentage of the manure input to the soil % Per vegetation type Maximum rooting depth 3
9. History of atmospheric pco2-levels (time series) Year Before Present pco 2 bar 10. Bioturbation history as intensity with depth (time series) Year= simulation year (oldest year = 1); Upper depth of bioturbation (usually 0: the soil surface) Depth of maximal bioturbation Lower depth of bioturbation Magnitude of bioturbation at upper depth Bioturbset.txt: ppt Magnitude of (maximal) bioturbation at depth of maximal bioturbation Bioturbset.txt: ppt Magnitude of bioturbation at lower depth of bioturbation (usually 0). Bioturbset.txt: ppt 11. Fertilization history (time series) Year Before Present Ca Mg Na K Cl SO4 HCO3 CO3 mol m -2 12. Event history Per year one option of the following (or nothing) Simulation year, Deposition, nr compartments added, Clay Silt OC Units as in soil data file BulkDensity MoistureContent Calcite Gypsum pco2 Ca-sol Mg-sol Na-sol K- sol Cl-sol SO4-sol Alkalinity Al-sol Org3-sol HOrg-sol H2Org-sol DOC Ca-exch Mg-exch Na-exch K-exch H-exch Al-exch CEC Mg/Ca-select Ca/Na-select Ca/K-select Ca/Al-select Ca/H-select (longer list including minerals for SoilGen2.25+) Simulation year, Erosion, nr compartments removed Simulation year, WaterTable, depth as nr compartments Simulation year, VGNChange, nr of compartments involved, <filename> <filename> points to a file with Van Genuchten parameters that may have been measured in a certain year Simulation year, Plowing, nr of compartments involved, mixed by plowing Simulation year, SlashBurn, nr of compartments involved, c lost to atmosphere (=CO2), c lost to charcoal (=IOM), c lost to humus 13. Process constants This file is only to be changed when the model is to be calibrated. See the user manual at http://users.ugent.be/~pfinke/index_bestanden/soilgen%20user%20manual.pdf 14. Model outputs Soil variable Units Soil variable Units Water Chemistry 4
Potential (kpa) Cation Exchange Capacity (ol+ / kg soil) Water content (cm.3 / cm.3) exchangeable cations (K, Na, (ol+ / kg soil) Mg, Ca, Al) Flux () Base Saturation (%) Evapotranspiration () Ions in solution (K, Na, Ca, Mg, Al, HCO3, CO3, Cl, SO4) Plant-available water (cm.3 / cm.3) ph, ph1:5 (-log mol / l) Mineralogy and weathering indices Alkalinity (ol- / l) Elements in minerals (mol / m2) Sodium Adsorption Ratio (-) (Ca, Mg, Na, K, Fe, Si, Al) Minerals (17 predefined, (kg / m2) EC (ms / m) plus 2 user- defined minerals) CIA (% Nesbitt+Young1982) ESP (%) IndexB (- Kronberg+Nesbitt1981) Biotics CIW (% Harnois1988) Roots (fraction of total) CPA (% BuggleEtAl2011) OC (mass % solid fraction) PIA (% FedoEtAl1995) Decomposable Plant Material (Mg / ha) DPM WI (- PriceEtAl1991) Resistant Plant Material RPM (Mg / ha) Total Reserve Of (cmol+ / kg soil) Biomass BIO (Mg / ha) Bases Physics Humus HUM (Mg / ha) bulk density (kg / dm.3) Inert Organic Matter IOM (Mg / ha) Clay (mass% fine earth) pco2 (bar) Silt (mass% fine earth) delta14c (per mil) Sand (mass% fine earth) 14C-age (14C years before simulation year) Porosity (volume fraction) 14C-per mil contributions per (14C per mil / C in pool) pool (DPM, RPM, BIO, HUM, IOM) Clay (volume%) Clay Dispersion (-) Indicator Temperature ( C) 5