Validation of Oryza 2000 Model with Irrigated Low Land Field Experiment of Rice

Abstract

Biophysical models predict the behavior of the land use system in physical terms such as crop yields, environmental effects, and effect on management. Oryza 2000 model Is an eco-physlologlcal crop model to simulate the growth and development of a rice crop in situations of potential production, water limitations, and nitrogen limitations. This paper reports on the calibration and validation of the model using Independent data sets of kharif rice crop. Data are originated from the nitrogen balance experiment conducted by Directorate of Rice Research (DRR), Hyderabad during 2001 .The calibration of the model was performed by deriving the crop growth parameters for DRRHl and Vikas varieties. Results show that there was overestimation of Leaf Area Index (LAl) in all our observations and there was slight overestlmation between simulated and observed weights of the total aboveground dry matter (WAGT and WAGT_OB5) of DRRH1 (13.7%) and Vikas (10.5%) varieties. At maturity date, with respect to grain yield (WRR14) parameter, model has shown slight overestimation with average of observed values of DRRHI (9.5%) and Vlkas (4.3 %). But in each case one of the replications of observed values very nearer to simulated values. Model simulations can be further improved by calibrating other parameters of crop. Hence, calibration to the model at different levels with more intensive field experimental data will Improve the performance of the model and it can be effectively used for different management practices for irrigated rice grown in dry season or wet season.