NITROGEN UPTAKE IN FIELD VEGETABLE PRODUCTION: MODELING BROADCAST AND ROW APPLICATION

Field vegetable production is characterized by a high residual soil nitrate content, leading to high leaching losses. A better understanding of the nitrogen balance under common farming practices can contribute to a more sensible nitrogen management. Simulation models can help to achieve this goal. In this study, a novel approach is presented to model the nitrogen uptake under broadcast and row application of fertilizer via a quasi 2-D approach. In this approach a mechanistic 1-D soil model is supplemented with a generic crop module. Parallel simulations are performed for a rooted field fraction and a rootless field fraction and information between these simulations is exchanged and updated on a daily basis. Validation of this approach was done in a field experiment with cauliflower. Via the quasi 2-D approach it was possible to simulate an increased nitrogen uptake with row application, although this was not represented in the measured data.