CERES-wheat model calibration/validation and use for risk assessment of adverse impacts of fertilisers in Bulgaria

摘要

Climate characteristics, water balance parameters and yield of wheat vary substantially over years and soil conditions in Bulgaria. Agricultural practices, especially fertiliser use, modify water transfer and N-uptake associated with this crop and thus the risk of groundwater pollution. The objective of this paper is to test and adjust CERES-wheat model to the typical agricultural conditions in Bulgaria and afterwards to use it for risk assessment analysis under different situations. CERES-wheat model was calibrated during a trial in 1996/97 and validated during the following trial in 1997/98, under impermeable Vertisol soil conditions in Bojurishte (Sofia region). Two levels of nitrogen (0 and 200 kg N/ha) were applied. Water retention and conductivity data measured in laboratory and in the field were compared to literature and used to specify the soil parameters of the model (Fig. 1 -left).