Validation of Oryza2000 model under combined nitrogen and water limited situations

Abstract

Oryza2000 is an eco-physiological crop model to simulate growth and development of rice in situations of potential production, water limitations, and nitrogen limitations. In the present investigation, unlike independent situation, the applicability under conditions of both water and N limitations has been investigated using data generated from field experiments over 5 years on long and short duration rice varieties. At higher N level model performs better for TDM and yield performance long duration varieties compared to short (Rasi) and medium duration (Ajaya) varieties. On the other, overestimation of leaf area index (LAI) at all nitrogen levels was consistent indicating a need in this area for further improvement of the model. In this context, model performance was also assessed by statistical analysis (R2 , D-index and NOF). D-index is ~0.8–0.9 for two varieties at 3 nitrogen application levels for Ajaya and BPT varieties. The results indicated applicability of model Oryza2000 can be extended to rice genotypes varying in their growth periods and situations like fertilizer, water limited conditions.