Agriculture Reference
In-Depth Information
Table 10.3. Soil datasets required as inputs for crop simulation models.
Minimum
Desirable for Specific
Applications
Initial Conditions
Lower limit water content at
10- to 20-cm depths
Hydraulic conductivity and water
retention curves at 10- to 20-cm
depths
Water content at 10- to 20-cm
depths
Field capacity soil water
content at 10- to 20-cm depths
Runoff curve number
Soil nitrate concentration at 10- to
20-cm depths
Crop rooting depth
Surface albedo
Soil ammonium concentration at
10- to 20-cm depths
Hydraulic conductivity at soil
depths that restrict water flow
Soil pH at 10- to 20-cm depths
Soil extractable phosphorus at
10- to 20-cm depths (if phosphorus
subroutine is run)
Soil organic carbon in upper
depths
Fresh plant residues or manure
amounts and depth of incorporation
Soil textural characterization for
10- to 20-cm depths
Surface water ponding capacity
Soil bulk density at 10- to 20-cm
depths
Groundwater depth bypass flow
fraction
Source
: Ritchie and Alagarswamy (2002).
Table 10.4. Crop management datasets required as inputs for crop simulation
models.
Minimum
Optional
Crop cultivar characteristics
Row spacing
Planting date and depth
Row direction
Plant population density
Pesticide inputs
Irrigation inputs (date, amount, depth)
Harvest date
Fertilizer inputs (date, amount, type)
Crop residues or manure inputs
(dates, quality, amount)
Source:
Ritchie and Alagarswamy (2002).
The crop variety, genotype, or cultivars also must be specified; cultivars may
vary significantly in the duration of developmental phases and in the partitioning
of assimilates within the plant. Wheat and corn cultivar information is generally
expressed as genetic coefficients, which allow models to simulate crop phenology
over a wide range of latitudes and planting times.
