WOFOST model description
WOFOST is a semi-deterministic crop simulation model of physiological processes such as crop phenology, light interception, photosynthesis (i.e., assimilation of carbohydrates), respiration, assimilate partitioning, leaf area dynamics, evapotranspiration and soil water balance. Crop growth and development is simulated with WOFOST on a daily time step from sowing to physiological maturity. Crop growth over time takes into account the amount of assimilates produced through photosynthesis and the amount of assimilates required for maintenance respiration. The difference between both rates is then partitioned to the different crop organs (i.e., roots, stems, leaves and grain) using partitioning coefficients specified according to the development stage of the crop. The development stage is calculated by integrating the daily development rate over time, which is a function of temperature. The current version of the model simulates potential or water-limited production. Simulations of potential production consider only the response of the crop to weather conditions, while simulations of water-limited production also take into account crop responses to soil moisture conditions. The growth-defining factors considered to simulate potential production include temperature, day-length, solar radiation and a set of crop parameters describing leaf area dynamics, assimilation characteristics and dry matter partitioning. Daily crop growth is estimated as the difference between the daily gross CO2 assimilation rate and the respiration rate. The former is calculated from the absorbed solar radiation assuming a photosynthesis light response curve of individual leaves. For water-limited conditions, the soil moisture content determines whether or not crop growth is limited by drought stress. For this purpose, a soil water balance is simulated over time applying a tipping bucket approach in the rooted zone. The soil water balance considers rainfall and irrigation as inputs and water losses by surface runoff, soil evaporation, crop transpiration and downward percolation as outputs. More information can be found here
DAISY Model description
DAISY is a soil-plant-atmosphere system dynamic model for agro-ecosystems, which simulates plant growth and soil processes based on the input of weather data (temperature, precipitation, global radiation and evapotranspiration), soil data (sand, silt and clay content, C:N ratio, bulk density and soil organic matter content), hydraulic parameters, location of ground water and management information. Management data required are crop rotation, tillage, use of fertilizer and manure, irrigation, sowing and harvesting. The model simulates water, heat, carbon and nitrogen flows in a soil-plant system at field scale and provides information on crop productivity, soil carbon, nutrient and water dynamics as a result of management and weather conditions at a particular site of interest. Daisy simulates at field scale and can describe processes like soil water transport and flow, evapotranspiration, crop development and growth dynamics. Daisy model can be linked up to other hydrological models has been validated in several international comparative validation studies.
