[Control Records]

i_Century Home Page i_Century Table List

# Field name Century name Units Type Default Comment
1 ID Long integer 0 Primary unique key. One per EPIC run. Links all records in tables Control Records, Field Operations, Output Annual, Output Annual Crop Yields, and Parameters
2 Description Text(80) Allow Zero Length = Yes
3 State FIPS Integer Not passed to Century
4 County FIPS Integer Not passed to Century
5 MLRA Text (5) Not passed to Century. Allow Zero Length = Yes
6 HUC Long integer Not passed to Century
7 PSU Long integer Not passed to Century
8 Point Integer Not passed to Century
9 Rotation Byte Not passed to Century
10 Tillage Byte Not passed to Century
11 Irrigation Byte Not passed to Century.
12 NRI Crop 1992 Integer Not passed to Century.
13 Soil ID Long integer 0 Link to table [Soils]. Not passed to Century
14 Weather ID Long Integer 0 Link to table [Weather by Months]. Not passed to Century
15 Latitude

degrees

0
16 Longitude

degrees

0
17 Hydric     Byte   Not passed to Century.
18 AGPPA AGPPA g/m2/y -40 Intercept parameter in the equation estimating potential aboveground biomass production for calculation of root/shoot ratio (used only if frtc(1) = 0)
19 AGPPB AGPPB g/m2/y/cm Single Precision Floating Point 7.7 Slope parameter in the equation estimating potential aboveground biomass production for calculation of root/shoot ratio (used only if frtc(1) = 0) NOTE - agppb is multiplied by annual precipitation (cm)
20 ANEREF(1) ANEREF(1) Single Precision Floating Point 0.9 Ratio of rain/potential evapotranspiration below which there is no negative impact of soil anaerobic conditions on decomposition
21 ANEREF(2) ANEREF(2) Single Precision Floating Point 2 Ratio of rain/potential evapotranspiration below which there is maximum negative impact of soil anaerobic conditions on decomposition
22 ANEREF(3) ANEREF(3) Single Precision Floating Point 0.1 Minimum value of the impact of soil anaerobic conditions on decomposition; functions as a multiplier for the maximum decomposition rate
23 ANIMPT Single Precision Floating Point 15 Slope term used to vary the impact of soil anaerobic conditions on decomposition flows to the passive soil organic matter pool
24 BGPPA g/m2/y Single Precision Floating Point 100 Intercept parameter in the equation estimating potential belowground biomass production for calculation of root/shoot ratio (used only if frtc(1) = 0)
25 BGPPB Years g/m2/y Single Precision Floating Point 7 Slope parameter in the equation estimating potential belowground biomass production for calculation of root/shoot ratio (used only if frtc(1) = 0) NOTE - bgppb is multiplied by annual precipitation (cm)
26 CO2PPM(1) ppm Single Precision Floating Point 350 Initial parts per million for CO2 effect
27 CO2PPM(2) ppm Single Precision Floating Point 640 Final parts per million for CO2 effect
28 CO2RMP Byte 1 Flag indicating whether CO2 effect should be: 0=step function 1=ramp function
29 DAMR(1,1) 0 Fraction of surface E absorbed by residue, N
30 DAMR(1,2) Single Precision Floating Point 0 Fraction of surface E absorbed by residue, P
31 DAMR(1,3) 0 Fraction of surface E absorbed by residue, S
32 DAMR(2,1) 0.02 Fraction of soil E absorbed by residue, N
33 DAMR(2,2) 0.02 Fraction of soil E absorbed by residue, P
34 DAMR(2,3) Single Precision Floating Point 0.04 Fraction of soil E absorbed by residue, S
35 DAMRMN(1) Single Precision Floating Point 15.0 Minimum C/E ratio allowed in residue after direct absorption, N
36 DAMRMN(2) Single Precision Floating Point 150 Minimum C/E ratio allowed in residue after direct absorption, P
37 DAMRMN(3) Single Precision Floating Point 150 Minimum C/E ratio allowed in residue after direct absorption, S
38 DEC1(1) Single Precision Floating Point 3.9 Maximum surface structural decomposition rate
39 DEC1(2) 4.9 Maximum soil structural decomposition rate
40 DEC2(1) 14.8 Maximum surface metabolic decomposition rate
41 DEC2(2) 18.5 Maximum soil structural decomposition rate
42 DEC3(1) 6.0 Maximum decomposition rate of surface organic matter with active turnover
43 DEC3(2) 7.3 Maximum decomposition rate of soil organic matter with active turnover
44 Dec4 0.0045 Maximum decomposition rate of soil organic matter with slow turnover
45 Dec5 0.2 Maximum decomposition rate of soil organic matter with intermediate turnover
46 DECK5 5.0 Available soil water content at which shoot and root death rates are half maximum (cm)
47 DLIGDF Single Precision Floating Point -4.0 Difference in delta 13C for lignin compared to whole plant delta 13C
48 DRESP Single Precision Floating Point 0.999 Discrimination factor for 13C during decomposition of organic matter due to microbial respiration
49 EDEPTH Single Precision Floating Point 0.2 Depth of the single soil layer where C, N, P, and S dynamics are calculated (only affects C, N, P, S loss by erosion)
50 ELITST Single Precision Floating Point 0.4 Effect of litter on soil temperature relative to live and standing dead biomass
51 ENRICH Single Precision Floating Point 2 Enrichment factor for SOM losses
52 FAVAIL(1) Single Precision Floating Point 0.9 Fraction of N available per month to plants
53 FAVAIL(3) Single Precision Floating Point 0.5 Fraction of S available per month to plants
54 FAVAIL(4) Single Precision Floating Point 0.2 Minimum fraction of P available per month to plants
55 FAVAIL(5) Single Precision Floating Point 0.4 Maximum fraction of P available per month to plants
56 FAVAIL(6) gN/m^2 Single Precision Floating Point 2 Mineral N in surface layer corresponding to maximum fraction of P available
57 FLEACH(1) Single Precision Floating Point 0.2 Intercept value for a normal month to compute the fraction of mineral N, P, and S which will leach to the next layer when there is a saturated water flow; normal leaching is a function of sand content
58 FLEACH(2) Single Precision Floating Point 0.7 Slope value for a normal month to compute the fraction of mineral N, P, and S which will leach to the next layer when there is a saturated water flow; normal leaching is a function of sand content
59 FLEACH(3) 1 Leaching fraction multiplier for N to compute the fraction of mineral N which leaches to the next layer when there is a saturated water flow; normal leaching is a function of sand content
60 FLEACH(4) 0 Leaching fraction multiplier for P to compute the fraction of mineral P which leaches to the next layer when there is a saturated water flow; normal leaching is a function of sand content
61 FLEACH(5) 0.1 Leaching fraction multiplier for S to compute the fraction of mineral S which leaches to the next layer when there is a saturated water flow; normal leaching is a function of sand content
62 FWLOSS(1) 0.8 Scaling factor for interception and evaporation of precipitation by live and standing dead biomass
63 FWLOSS(2) 0.8 Scaling factor for bare soil evaporation of precipitation (h2olos)
64 FWLOSS(3) Single Precision Floating Point 0.65 Scaling factor for transpiration water loss (h2olos)
65 FWLOSS(4) 0.75 Scaling factor for potential evapotranspiration (pevap)
66 FXMCA -0.125 Intercept for effect of biomass on non-symbiotic soil N fixation; used only when nsnfix = 1
67 FXMCB 0.005 Slope control for effect of biomass on non-symbiotic soil N fixation; used only when nsnfix = 1
68 FXMXS 0.35 Maximum monthly non-symbiotic soil N-fixation rate (reduced by effect of N:P ratio, used when nsnfix = 1)
69 FXNPB 7 N/P control for N-fixation based on availability of top soil layer (used when nsnfix = 1)
70 GREMB 0 Grazing effect multiplier for grzeff types 4, 5, 6
71 IDEF Byte 2 flag for method of computing water effect on decomposition
72 LHZF(1) 0.2 Lower horizon factor for active pool; = fraction of active pool (SOM1CI(2,*)) used in computation of lower horizon pool sizes for soil erosion routines
73 LHZF(2) 0.4 Lower horizon factor for slow pool; = fraction of slow pool (SOM2CI(*) used in computation of lower horizon pool sizes for soil erosion routines
74 LHZF(3) 0.8 Lower horizon factor for passive pool; = fraction of passive pool (SOM3CI(*) used in computation of lower horizon pool sizes for soil erosion routines
75 MINLCH 18 Critical water flow for leaching of minerals (cm of h2o leached below 30 cm soil depth)
76 NSNFIX 0 Equals 1 if non-symbiotic N fixation should be based on N:P ratio in mineral pool, otherwise non-symbiotic N fixation is based on annual precipitation
77 NTSPM 4 Number of time steps per month for the decomposition submodel
78 OMLECH(1) 0.03 Intercept for the effect of sand on leaching of organic compounds
79 OMLECH(2) 0.12 Slope for the effect of sand on leaching of organic compo
80 OMLECH(3) cm 60 Amount of water (cm) that needs to flow out of water layer 2 to produce leaching of organics
81 P1CO2A(1) 0.6 Intercept parameter which controls flow from surface organic matter with fast turnover to CO2 (fraction of C lost to CO2 when there is no sand in the soil)
82 P1CO2A(2) 0.17 Intercept parameter which controls flow from soil organic matter with fast turnover to CO2 (fraction of C lost to CO2 when there is no sand in the soil)
83 P1CO2B(1) 0 Slope parameter which controls flow from surface organic matter with fast turnover to CO2 (fraction of C lost to CO2 when there is no sand in the soil)
84 P1CO2B(2) Single Precision Floating Point 0.68 Slope parameter which controls flow from soil organic matter with fast turnover to CO2 (fraction of C lost to CO2 when there is no sand in the soil)
85 P2CO2 0.55 Controls flow from soil organic matter with intermediate turnover to CO2 (fraction of C lost as CO2 during decomposition)
86 P3CO2 0.55 Controls flow from soil organic matter with slow turnover to CO2 (fraction of C lost as CO2 during decomposition)
87 PABRES 100 Amount of residue which will give maximum direct absorption of N (Gc/m^2)
88 PCEMIC(1,1) 16.0 maximum C/E ratio for surface microbial pool, N
89 PCEMIC(1,2) 200.0 maximum C/E ratio for surface microbial pool, P
90 PCEMIC(1,3) 150.0 maximum C/E ratio for surface microbial pool, S
91 PCEMIC(2,1) 10.0 Minimum C/E ratio for surface microbial pool, N
92 PCEMIC(2,2) 99.0 Minimum C/E ratio for surface microbial pool, P
93 PCEMIC(2,3) 50.0 Minimum C/E ratio for surface microbial pool, S
94 PCEMIC(3,1) 0.02 Minimum E content of decomposing aboveground material above which the C/E ratio of the surface microbes equals pcemic(2,*), N
95 PCEMIC(3,2) 0.0015 Minimum E content of decomposing aboveground material above which the C/E ratio of the surface microbes equals pcemic(2,*), P
96 PCEMIC(3,3) 0.0015 Minimum E content of decomposing aboveground material above which the C/E ratio of the surface microbes equals pcemic(2,*), S
97 PEFTXA 0.25 Intercept parameter for regression equation to compute the effect of soil texture on the microbe decomposition rate (the effect of texture when there is no sand in the soil)
98 PEFTXB 0.75 Slope parameter for regression equation to compute the effect of soil texture on microbe decomposition rate; the slope is multiplied by the sand content fraction
99 PHESP(1) 6 Minimum pH for determining the effect of pH on the solubility of secondary P (flow of secondary P to mineral P) (for texesp(2) = m * (pH input) + b, m and b calculated using these phesp values)
100 PHESP(2) 0.0008 Value of texesp(2), the solubility of secondary P, corresponding to minimum pH (/yr)
101 PHESP(3) 7.6 Maximum pH for determining effect on solubility of secondary P (flow of secondary P to mineral P) (for texesp(2) = m * (pH input) + b, m and b calculated using these phesp values)
102 PHESP(4) 0.015 Value of texesp(2), the solubility of secondary P, corresponding to maximum pH (/yr)
103 PLIGST(1) 3 Effect of lignin on surface structural or fine branch and large wood decomposition
104 PLIGST(2) 3 Effect of lignin on soil structural or coarse root decomposition
105 PMCO2(1) 0.55 Controls flow from metabolic to CO2 (fraction of C lost as CO2 during decomposition), surface
106 PMCO2(2) 0.55 Controls flow from metabolic to CO2 (fraction of C lost as CO2 during decomposition), soil
107 PMNSEC(1) Single Precision Floating Point 0 Slope for E; controls the flow from mineral to secondary N (/yr), N
108 PMNSEC(2) 0 Slope for E; controls the flow from mineral to secondary N (/yr), P
109 PMNSEC(3) 2 Slope for E; controls the flow from mineral to secondary N (/yr), S
110 PMNTMP 0.004 Effect of biomass on minimum surface temperature

111

PMXBIO

600

Maximum dead biomass (standing dead + 10% litter) level for soil temperature calculation and for calculation of the potential negative effect on plant growth of physical obstruction by standing dead and surface litter

112 PMXTMP 0.0035 Effect of biomass on maximum surface temperature
113 PPARMN(1) 0 Controls the flow from parent material to mineral compartment (fraction of parent material that flows to mineral E), N
114 PPARMN(2) 0.0001 Controls the flow from parent material to mineral compartment (fraction of parent material that flows to mineral E), P
115 PPARMN(3) 0.0005 Controls the flow from parent material to mineral compartment (fraction of parent material that flows to mineral E), S
116 PPRPTS(1) 0 Minimum ratio of available water to PET which would completely limit production assuming WC = 0
117 PPRPTS(2) 1 Effect of WC on the intercept
118 PPRPTS(3) 0.8 Lowest ratio of available water to PET at which there is no restriction on production
119 PS1CO2(1) 0.45 Controls amount of CO2 loss when structural decomposes to som1, subscripted for surface and soil layer, surface
120 PS1CO2(2) 0.55 Controls amount of CO2 loss when structural decomposes to som1, subscripted for surface and soil layer, soil
121 PS1S3(1) Single Precision Floating Point 0.003 Intercept for effect of clay on the control for the flow from soil organic matter with fast turnover to som with slow turnover (fraction of C from som1c to som3c)
122 PS1S3(2) Single Precision Floating Point 0.032 Slope for effect of clay on the control for the flow from soil organic matter with fast turnover to som with slow turnover (fraction of C from som1c to som3c)
123 PS2S3(1) 0.003 Slope value which controls flow from soil organic matter with intermediate turnover to soil organic matter with slow turnover (fraction of C from som2c to som3c)
124 PS2S3(2) 0.009 Intercept value which controls flow from soil organic matter with intermediate turnover to soil organic matter with slow turnover (fraction of C from som2c to som3c)
125 PSECMN(1) 0 Controls the flow from secondary to mineral E, N
126 PSECMN(2) 0.0022 Controls the flow from secondary to mineral E, P
127 PSECMN(3) 0.2 Controls the flow from secondary to mineral E, S
128 PSECOC1 Single Precision Floating Point

0 Controls the flow from secondary to occluded P
129 PSECOC2 Single Precision Floating Point 0
130 RAD1P(1,1) 12 Intercept used to calculate addition term for C/E ratio of slow SOM formed from surface active pool, N
131 RAD1P(2,1) 3 Slope used to calculate addition term for C/E ratio of slow SOM formed from surface active pool, N
132 RAD1P(3,1) 5 Minimum allowable C/E used to calculate addition term for C/E ratio of slow SOM formed from surface active pool, N
133 RAD1P(1,2) 220 Intercept used to calculate addition term for C/E ratio of slow SOM formed from surface active pool, P
134 RAD1P(2,2) 5 Slope used to calculate addition term for C/E ratio of slow SOM formed from surface active pool, P
135 RAD1P(3,2) 100 Minimum allowable C/E used to calculate addition term for C/E ratio of slow SOM formed from surface active pool, P
136 RAD1P(1,3) 220 Intercept used to calculate addition term for C/E ratio of slow SOM formed from surface active pool, S
137 RAD1P(2,3) 5 Slope used to calculate addition term for C/E ratio of slow SOM formed from surface active pool, S
138 RAD1P(3,3) 100 Minimum allowable C/E used to calculate addition term for C/E ratio of slow SOM formed from surface active pool, S
139 RCESTR(1) 200 C/E ratio for structural material, N
140 RCESTR(2) 500 C/E ratio for structural material, P
141 RCESTR(3) 500 C/E ratio for structural material, S
142 RICTRL 0.015 Root impact control term used by rtimp; used for calculating the impact of root biomass on nutrient availability
143 RIINT 0.8 Root impact intercept used by rtimp; used for calculating the impact of root biomass on nutrient availability
144 RSPLIG 0.3 Fraction of lignin flow (in structural decomposition) lost as CO2
145 SEED -1 Random number generator seed value
146 SPL(1) 0.85 Intercept parameter for metabolic (vs. structural) split
147 SPL(2) 0.013 Slope parameter for metabolic split (fraction metabolic is a function of lignin to N ratio)
148 STRMAX(1) gC/m2 5000 Maximum amount of structural material in surface layer that will decompose
149 STRMAX(2) gC/m2 5000 Maximum amount of structural material belowground that will decompose
150 TEFF(1) Exponential decomposition model
151 TEFF(2) Exponential decomposition model
152 TEFF(3) Exponential decomposition model
153 TEFF(4) ArcTan decomposition model
154 TEXEPP(1) Boolean 1 Texture effect on parent P mineralization: 1=include the effect of texture using the remaining texepp values with the arctangent function, 0=use pparmn(2) in the weathering equation
155 TEXEPP(2) Single Precision Floating Point 0.7 x location of inflection point used in determining texture effect on parent P mineralization
156 TEXEPP(3)

0.0001 y location of inflection point used in determining texture effect on parent P mineralization
157 TEXEPP(4)

0.00016 Step size (distance from the maximum point to the minimum point) used in determining texture effect on parent P mineralization
158 TEXEPP(5)

2 Slope of the line at the inflection point used in determining texture effect on parent P mineralization
159 TEXESP(1) 1 Texture effect on secondary P flow to mineral P: 1=include the effect of pH and sand content using the equation specified by texesp(2) (a function of pH and phesp(1-4)) and texesp(3), 0=to use psecmn(2) in the weathering equation
160 TEXESP(3) 0.004 slope value used in determining effect of sand content on secondary P flow to mineral P
161 TMAX deg. C 45 Maximum temperature for decomposition
162 TMELT(1)   -8 Minimum temperature above which at least some snow will melt
163 TMELT(2)   4 Ratio between degrees above the minimum and cm of snow that will melt
164 TOPT deg. C 35 Optimum temperature for decomposition
165 TSHL 2.63 Shape parameter to left of optimum temperature (for decomposition)
166 TSHR 0.2 Shape parameter to left of optimum temperature (for decomposition)
167 VARAT1(1,1)   14 Maximum C/E ratio for material entering som1, N
168 VARAT1(2,1)   3 Minimum C/E ratio for material entering som1, N
169 VARAT1(3,1)   2 Amount of E present when minimum ratio applies, N
170 VARAT1(1,2) 150 Maximum C/E ratio for material entering som1, P
171 VARAT1(2,2) 30 Minimum C/E ratio for material entering som1, P
172 VARAT1(3,2) 2 Amount of E present when minimum ratio applies, P
173 VARAT1(1,3) 200 Maximum C/E ratio for material entering som1, S
174 VARAT1(2,3) 50 Minimum C/E ratio for material entering som1, S
175 VARAT1(3,3) 2 Amount of E present when minimum ratio applies, S
176 VARAT2(1,1) 20 Maximum C/E ratio for material entering som2, N
177 VARAT2(2,1) 12 Minimum C/E ratio for material entering som2, N
178 VARAT2(3,1) 2 Amount of E present when minimum ratio applies, N
179 VARAT2(1,2) 400 Maximum C/E ratio for material entering som2, P
180 VARAT2(2,2) 100 Minimum C/E ratio for material entering som2, P
181 VARAT2(3,2) 2 Amount of E present when minimum ratio applies, P
182 VARAT2(1,3) 400 Maximum C/E ratio for material entering som2, S
183 VARAT2(2,3) 100 Minimum C/E ratio for material entering som2, S
184 VARAT2(3,3) 2 Amount of E present when minimum ratio applies, S
185 VARAT3(1,1) 8 Maximum C/E ratio for material entering som3, N
186 VARAT3(2,1) 6 Minimum C/E ratio for material entering som3, N
187 VARAT3(3,1) 2 Amount of E present when minimum ratio applies, N
188 VARAT3(1,2) 200 Maximum C/E ratio for material entering som3, P
189 VARAT3(2,2) 50 Minimum C/E ratio for material entering som3, P
190 VARAT3(3,2) 2 Amount of E present when minimum ratio applies, P
191 VARAT3(1,3) 200 Maximum C/E ratio for material entering som3, S
192 VARAT3(2,3) 50 Minimum C/E ratio for material entering som3, S
193 VARAT3(3,3) 2 Amount of E present when minimum ratio applies, S
194 VLOSSE 0.05 Fraction per month of excess N (i.e. N left in the soil after nutrient uptake by the plant) which is volatilized
195 VLOSSG 0.02 Fraction per month of gross mineralization which is volatized
196 XEFCLTEF 0.25
197 Labeling Type C_LABELING Byte
198 Labeling Year Short integer
199 Simulate Microcosm SCHED_MICRO Boolean
200 Simulate CO2 Effect CO2_EFFECT Boolean
201 Initial System Byte 1=Cropping/Grassland, 2=Forest, 3=Cropping/Grassland and Forest
202 Initial Crop Text(5) Key to table [Crops].  If none specified, first member of crop list is used.
203 Initial Tree Text(5) Key to table [Trees].  If none specified, first member of tree list is used.
204 Organic Matter Decomposition Model     Byte   1=Density, 2=Exponential, 3=ArcTan
205 pH Shift Year     Short integer    
206 Soil Warming Year     Short integer    
207 Soil Warming        
208 N Scalar Option     Byte    
209 N Scalar Year     Short integer    
210 OMAD Scalar Year     Short integer    
211 Climate Scalar Option     Byte    
212 Climate Scalar Year     Short integer