Modeling Resource Use Efficiency of Transplanted Rice for Irrigated Conditions in a Semiarid Environment.

Crop simulation models (CSM) are being intensively all over the world as research tools. These models provide an economical and time saving option to determine the crop requirements for optimizing yield, maximizing net returns for a range of management practices and ultimately food security. The goal of this study was to evaluate the potential of the resources use efficiency of field grown rice by using CERES-Rice and also to simulate rice yield at various nitrogenous and irrigation regimes under irrigated semiarid environmental conditions of Faisalabad, Pakistan. The model was calibrated and evaluated with field data collected during 2000 and 2001 for one rice variety Basmnati-385, five nitrogenous rates (0, 50, 100, 150 and 200 kg ha^‑1) and five irrigation regimes (62.5, 77.5, 92.5, 107.5 and 122.5 cm) under irrigated semiarid environmental conditions of Faisalabad, Pakistan. The results showed that the CSM-CERES-Rice model can be used consistently for prediction of phenology, growth and yield of rice under semiarid environmental conditions. To determine the optimum nitrogen and irrigation level, the model was run with different nitrogen and irrigation treatments and 30 years of historical weather data. The results of both biophysical and economic analysis showed that a minimum of 200 kg N ha^-1 and 107.5 cm are the optimum nitrogen and irrigation levels under irrigated semiarid environment. This study showed that the CSM-CERES–Rice can be a useful and successful tool for determining the maximum efficiency of resources of rice under semiarid environmental conditions.