SIMULATION OF WATER AND NITROGEN DYNAMICS AT 3 DANISH LOCATIONS BY USE OF THE DAISY MODEL

Results from simulation of water and nitrogen dynamics by use of the d ynamic model DAISY are shown. The simulations included a test of DAISY on data from research stations representing different soil types, pre cipitation regimes and fertilizer strategies. DAISY is mainly a determ inistic and mechanistic model, but there are also empirical parts, as for example the crop production model. The originally proposed paramet ers overestimated the nitrogen uptake in the crops, and thereby leachi ng was underestimated. Adjustments in the crop parameters related to s pring barley and potatoes are proposed. With these adjustments the pre sent test shows a satisfactory agreement between measured and simulate d dry matter production, nitrogen uptake and leaching.