Each computer model requires a set of data as input. The Minimum Data Set (MDS) concept was first introduced during a workshop held at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) in Patancheru, India. MDS refers both to the minimum data required to run a crop model and the minimum data required to evaluate the crop model simulation outputs.
In order to run a crop model the following data are required:
- Site weather data for the duration of the growing season, but preferably for the complete year
- Soil surface characteristics and soil profile data
- Crop management from the experiment that was conducted for model calibration
For crop model calibration and evaluation the crop model inputs listed previously are required, as well one more or more observations, including yield, yield components, and the main phenological dates for grain cereals and legumes, including the first flowering date and maturity date.
The minimum required weather data include:
- Latitude and longitude of the weather station,
- Daily values of incoming solar radiation (MJ/m²-day),
- Maximum and minimum daily air temperature (ºC), and
- Daily total rainfall (mm).
You may also include dry and wet bulb temperatures and wind speed, which allow for simulating evapotranspiration with more robust methods. The length of weather records for evaluation must, at minimum, cover the duration of the experiment and preferably should begin a few weeks before planting and continue a few weeks after harvest so that “what-if” type analyses may be performed.
Desired soil surface data include soil classification according to NRCS, formerly referred to as SCS, surface slope, color, permeability, and drainage class. Soil profile data by soil horizons include:
- upper and lower horizon depths (cm),
- percentage sand, silt, and clay content,
- 1/3 bar bulk density,
- organic carbon,
- pH in water,
- aluminum saturation, and
- root abundance information.
Management and Experimental Data
Management data includes information on planting date, dates when soil conditions were measured prior to planting, planting density, row spacing, planting depth, crop variety, irrigation, and fertilizer practices. These data are needed for both model evaluation and strategy analysis.
In addition to site, soil, and weather data, experimental data include crop growth data, soil water and fertility measurements. These are the observed data that are needed for model evaluation.