Simulating paddy crop response to irrigation using FAO AquaCrop model: a case study

Abstract

Crop production is directly related to the water used, which is a major constraint to meet food security for the growing population nowadays. Attempts were made to understand the response of paddy to irrigation by using the FAO AquaCrop model for crop yield data of 8-years. Weather parameters were analyzed for paddy crop growing period to validate the model; crop parameters were calibrated for paddy variety of 120 days duration in Ludhiana, India. Reference evapotranspiration (ET0) and irrigation schedule (718-1048.1 mm) was decided by using ET0 calculator and CROPWAT model, respectively. The simulated yield (3.80-4.53 t ha-1) was validated with the actual yield (3.53-4.63 t ha-1) with water use efficiency (3.1-3.7 kg ha-1 mm-1), obtained during the years of observation. The model was evaluated with the percentage error of 0.59, root mean square error of 0.064, mean absolute error of 0.06 indicating higher accuracy of the calibrated model. Thus the model would be useful for predicting the paddy crop yield, irrigation water productivity under different irrigation scenarios.