The CropSyst Model to Simulate the N Balance of Rice for Alternative Management

The very low levels of nitrogen efficiency in rice production probably represent the main weak point of the modern intensive rice-culture, tremendously affecting economic and ecological sustainability. Simulation models can be considered useful tools for a real system analysis, needed to individuate the best site-specific fertilizer management with high efficiency. For calibrating and validating CropSyst (for the first time used for nitrogen balance simulations in paddy fields) by considering the nitrogen cycle in submerged soil, data obtained from three field experiments, carried out in Northern Italy between 2002 and 2004 were used. Mineralization, nitrification and denitrification rate adjustments (dimensionless; 0.00 – 2.00) were calibrated (final values ranging between 1.30 and 1.95; 0.06 and 0.40 for the first two coefficients and equal to 1.90 for the third), by comparing measured and simulated soil mineral nitrogen concentration data. CropSyst simulated soil N-NO3 and N-NH4 concentration with discrete accuracy: in spite of RRMSE values not always satisfactory, the values of the Coefficient of Residual Mass are always close to 0; Coefficient of Determination is in most cases close to 1 and Modelling Efficiency is almost always positive. The other terms of nitrogen balance were discussed.

CONFALONIERI Roberto;  GUSBERTI Davide;  BOCCHI Stefano;  ACUTIS Marco; 

2007-01-23

E D P SCIENCES

JRC31492

https://publications.jrc.ec.europa.eu/repository/handle/JRC31492,   

10.1051/agro:2006022,