Crop Parameters


BIOFLG - Value indicating whether production should be reduced by physical obstruction: BIOFLG is a continuous measure ranging from 0 to 1, where the extremes are 0 = production should not be reduced at all, and 1 = production should be reduced completely.

BIOK5 - Level of aboveground standing dead + 10% STRUCC(1) C in grams of carbon per square meter (g C /m2) at which production is reduced to half maximum due to physical obstruction by the dead material. Used only when BIOFLG = 1.
Valid Range: 0.0 to 2000.0

BIOMAX - Biomass level above which the minimum and maximum C / E ratios of the new shoot increments equal PRAMN(*,2) and PRAMX(*,2) respectively, in grams of biomass per square meter (g biomass/m2).

Valid Range: 0.0 to 1000.0

CO2ICE(1,1,1) - In a grassland/crop system, the effect on minimum C / N ratio of doubling the atmospheric CO2 concentration from 350 ppm to 700 ppm. A value of 1 will have no effect. A reduction will have a negative effect. And an increase will have a positive effect.

Valid Range: 0.5 to 1.5

CO2ICE(1,1,2) - In a grassland/crop system, the effect on minimum C / P ratio of doubling the atmospheric CO2 concentration from 350 ppm to 700 ppm. A value of 1 will have no effect. A reduction will have a negative effect. And an increase will have a positive effect.

Valid Range: 0.5 to 1.5

CO2ICE(1,1,3) - In a grassland/crop system, the effect on minimum C / S ratio of doubling the atmospheric CO2 concentration from 350 ppm to 700 ppm. A value of 1 will have no effect. A reduction will have a negative effect. And an increase will have a positive effect.

Valid Range: 0.5 to 1.5

CO2ICE(1,2,1) - In a grassland/crop system, the effect on maximum C / N ratio of doubling the atmospheric CO2 concentration from 350 ppm to 700 ppm. A value of 1 will have no effect. A reduction will have a negative effect. And an increase will have a positive effect.

Valid Range: 0.5 to 1.5

CO2ICE(1,2,2) - In a grassland/crop system, the effect on maximum C / P ratio of doubling the atmospheric CO2 concentration from 350 ppm to 700 ppm. A value of 1 will have no effect. A reduction will have a negative effect. And an increase will have a positive effect.

Valid Range: 0.5 to 1.5

CO2ICE(1,2,3) - In a grassland/crop system, the effect on maximum C / S ratio of doubling the atmospheric CO2 concentration from 350 ppm to 700 ppm. A value of 1 will have no effect. A reduction will have a negative effect. And an increase will have a positive effect.

Valid Range: 0.5 to 1.5

CO2IPR(1) - In a grassland/crop system, the effect on plant production of doubling the atmospheric CO2 concentration from 350 ppm to 700 ppm. A value of 1 will have no effect. A reduction will have a negative effect. And an increase will have a positive effect.

Valid Range: 0.5 to 1.5

CO2IRS(1) - In a grassland/crop system, the effect on root-shoot ratio of doubling the atmospheric CO2 concentration from 350 ppm to 700 ppm. A value of 1 will have no effect. A reduction will have a negative effect. And an increase will have a positive effect.

Valid Range: 0.5 to 1.5

CO2ITR(1) - In a grassland/crop system, the effect on transpiration rate of doubling the atmospheric CO2 concentration from 350 ppm to 700 ppm. A value of 1 will have no effect. A reduction will have a negative effect. And an increase will have a positive effect.

Valid Range: 0.5 to 1.5

CRPRTF(1) - Fraction of N transferred to a vegetation storage pool from grass/crop leaves at death

Valid Range: 0.0 to 1.0

CRPRTF(2) - Fraction of P transferred to a vegetation storage pool from grass/crop leaves at death.

Valid Range: 0.0 to 1.0

CRPRTF(3) - Fraction of S transferred to a vegetation storage pool from grass/crop leaves at death.

Valid Range: 0.0 to 1.0

DEL13C - Delta 13C value for stable isotope labeling.

Valid Range: -30.0 to 0.0

EFRGRN(1) - Fraction of the aboveground N which goes to grain.

Valid Range: 0.0 to 1.0

EFRGRN(2) - Fraction of the aboveground P which goes to grain.

Valid Range: 0.0 to 1.0

EFRGRN(3) - Fraction of the aboveground S which goes to grain.

Valid Range: 0.0 to 1.0

FALLRT - Fall rate (fraction of standing dead which falls each month).

Valid Range: 0.0 to 1.0

FLIGNI(1,1) - Intercept for equation to predict lignin content fraction based on annual rainfall for aboveground material.

Valid Range: 0.0 to 1.0

FLIGNI(2,1) - Slope for equation to predict lignin content fraction based on annual rainfall for aboveground material. For crops, set to 0.

Valid Range: 0.0 to 1.0

FLIGNI(1,2) - Intercept for equation to predict lignin content fraction based on annual rainfall for belowground material.

Valid Range: 0.0 to 1.0

FLIGNI(2,2) - Slope for equation to predict lignin content fraction based on annual rainfall for belowground material. For crops, set to 0.

Valid Range: 0.0 to 1.0

FRTC(1) - Initial fraction of C allocated to roots; for Great Plains equation based on precipitation, set to 0.

Valid Range: 0.0 to 1.0

FRTC(2) - Final fraction of C allocated to roots.

Valid Range: 0.0 to 1.0

FRTC(3) - Time after planting (months with soil temperature greater than RTDTMP) at which the final value is reached; must not equal 0.

Valid Range: 1.0 to 12.0

FSDETH(1) - Maximum shoot death rate at very dry soil conditions (fraction/month); for getting the monthly shoot death rate, this fraction is multiplied times a reduction factor depending on the soil water status.

Valid Range: 0.0 to 1.0

FSDETH(2) - Fraction of shoots which die during senescence month; must be greater than or equal to 0.4.

Valid Range: 0.4 to 1.0

FSDETH(3) - Additional fraction of shoots which die when aboveground live C is greater than FSDETH(4).

Valid Range: 0.0 to 1.0

FSDETH(4) - The level of aboveground C above which shading occurs and shoot senescence increases.

Valid Range: 0.0 to 500.0

FULCAN - Value of AGLIVC at full canopy cover, above which potential production is not reduced

Valid Range: 50.0 to 200.0

HIMAX - Harvest index maximum (fraction of aboveground live C in grain). If a harvest event can be scheduled for this plant, the value should be > 0 (see the crop submodel for more information).

Valid Range: 0.0 to 1.0

HIMON(1) - Number of months prior to harvest in which to begin accumulating water stress effect on harvest index.

Valid Range: 0.0 to 12.0

HIMON(2) - Number of months prior to harvest in which to stop accumulating water stress effect on harvest index.

Valid Range: 0.0 to 12.0

HIWSF - Harvest index water stress factor:

0 = no effect of water stress upon grain yield.

1 = no grain yield with maximum water stress.

Valid Values: 0 to 1

PLTMRF - Planting month reduction factor to limit seedling growth; should be 1.0 for grass.

Valid Range: 0.0 to 1.0

PPDF(1) - Optimum temperature for production for parameterization of a Poisson Density Function curve to simulate temperature effect on growth.

Valid Range: 10.0 to 40.0

PPDF(2) - Maximum temperature for production for parameterization of a Poisson Density Function curve to simulate temperature effect on growth.

Valid Range: 20.0 to 50.0

PPDF(3) - Left curve shape for parameterization of a Poisson Density Function curve to simulate temperature effect on growth.

Valid Range: 0.0 to 1.0

PPDF(4) - Right curve shape for parameterization of a Poisson Density Function curve to simulate temperature effect on growth.

Valid Range: 0.0 to 10.0

PRAMN(1,1) - Minimum C / N ratio with zero biomass.

Valid Range: 1.0 to 100.0

PRAMN(2,1) - Minimum C / P ratio with zero biomass.

Valid Range: 1.0 to 9999.0

PRAMN(3,1) - Minimum C / S ratio with zero biomass.

Valid Range: 1.0 to 9999.0

PRAMN(1,2) - Minimum C / N ratio with biomass equal BIOMAX.

Valid Range: 1.0 to 200.0

PRAMN(2,2) - Minimum C / P ratio with biomass equal BIOMAX.

Valid Range: 1.0 to 9999.0

PRAMN(3,2) - Minimum C / S ratio with biomass greater than or equal to BIOMAX.

Valid Range: 1.0 to 9999.0

PRAMX(1,1) - Maximum C / N ratio with zero biomass.

Valid Range: 1.0 to 200.0

PRAMX(2,1) - Maximum C / P ratio with zero biomass.

Valid Range: 1.0 to 9999.0

PRAMX(3,1) - Maximum C / S ratio with zero biomass.

Valid Range: 1.0 to 9999.0

PRAMX(1,2) - Maximum C / N ratio with biomass equal BIOMAX.

Valid Range: 1.0 to 400.0

PRAMX(2,2) - Maximum C / P ratio with biomass equal BIOMAX.

Valid Range: 1.0 to 9999.0

PRAMX(3,2) - Maximum C / S ratio with biomass greater than or equal to BIOMAX.

Valid Range: 1.0 to 9999.0

PRBMN(1,1) - Intercept parameter for computing minimum C / N ratio for belowground matter as a linear function of annual precipitation.

Valid Range: 0.0 to 150.0

PRBMN(2,1) - Intercept parameter for computing minimum C / P ratio for belowground matter as a linear function of annual precipitation.

Valid Range: 0.0 to 9999.0

PRBMN(3,1) - Intercept parameter for computing minimum C / S ratio for belowground matter as a linear function of annual precipitation.

Valid Range: 0.0 to 9999.0

PRBMN(1,2) - Slope parameter for computing minimum C / N ratio for belowground matter as a linear function of annual precipitation.

Valid Range: 0.0 to 1.0

PRBMN(2,2) - Slope parameter for computing minimum C / P ratio for belowground matter as a linear function of annual precipitation.

Valid Range: 0.0 to 1.0

PRBMN(3,2) - Slope parameter for computing minimum C / S ratio for belowground matter as a linear function of annual precipitation.

Valid Range: 0.0 to 1.0

PRBMX(1,1) - Intercept parameter for computing maximum C / N ratios for belowground matter as a linear function of annual precipitation.

Valid Range: 0.0 to 300.0

PRBMX(2,1) - Intercept parameter for computing maximum C / P ratios for belowground matter as a linear function of annual precipitation.

Valid Range: 0.0 to 9999.0

PRBMX(3,1) - Intercept parameter for computing maximum C / S ratios for belowground matter as a linear function of annual precipitation.

Valid Range: 0.0 to 9999.0

PRBMX(1,2) - Slope parameter for computing maximum C / N ratios for belowground matter as a linear function of annual precipitation.

Valid Range: 0.0 to 1.0

PRBMX(2,2) - Slope parameter for computing maximum C / P ratios for belowground matter as a linear function of annual precipitation.

Valid Range: 0.0 to 1.0

PRBMX(3,2) - Slope parameter for computing maximum C / S ratios for belowground matter as a linear function of annual precipitation. Valid Range: 0.0 to 1.0

PRDX(1) - Potential aboveground monthly production for crops (g biomass/m2/month ). Valid Range: 1.0 to 9999.0

RDR - Maximum root death rate at very dry soil conditions (fraction/month); for getting the monthly root death rate, this fraction is multiplied times a reduction factor depending on the soil water status. Range: 0.0 to 1.0

RTDTMP - Physiological shutdown temperature for root death and change in shoot/root ratio. Valid Range: -5.0 to 5.0

SNFXMX(1) - Symbiotic N fixation maximum for grassland/crop (g N fixed/g C new growth). Valid Range: 0.0 to 1.0

VLOSSP - Fraction of aboveground plant N which is volatilized This is applied at harvest for grain crops and at senescence for grasses. Valid Range: 0.0 to 1.0