Parameter assessment for simulation of biomass production and nitrogen uptake in winter rape

Field experiments were conducted with winter rape at two locations in 1991/1992. The effects of three different amounts of nitrogen were compared. Plants were protected against weeds, diseases and pests and irrigated to minimize detrimental effects on yield. The results are used to assess a set of crop parameters for use in a dynamic simulation model for the soil-plant system, DAISY. The model is briefly described. The time course of biomass production, nitrogen uptake and green crop area index development is simulated for potential and for nitrogen-limited crop production. Results are compared with observations. The agreement was quite satisfactory for both locations. Shortcomings of the present model are demonstrated, however, in its ability to simulate nitrogen dynamics in plants late in the growth period and also in its ability to simulate green area index (and growth) during the autumn period.