Performance Evaluation of AquaCrop Model for Rabi Maize Crop in the North Bihar Condition

Abstract

A field experiment was conducted in Rabi season of 2016-17 at experimental field of AICRP on Irrigation Water Management, Dr. Rajendra Prasad Central Agricultural University, Pusa (Bihar), India. This experiment was undertaken to study the response to evaluate the FAO­-AquaCrop model for Rabi maize at different levels of irrigation. Crop growth simulation models of varying complexity have been developed for predicting the effects of soil, water and nutrients on grain and biomass yields and water productivity of different crops. The experiment was laid out in randomized block design with four treatment, five replication and five irrigations were applied in the main plot. The irrigation treatments consisted of all possible combinations of full irrigation or limited irrigation in such that T1 (full/control irrigation), T2 (75% of CI), T3 (50% of CI) and T4 (Rainfed / No Irrigation). The AquaCrop model evaluated for grain yield and biomass under different irrigation levels resulted in prediction error ranging from 2.25% to 9.59% and 2.44% to 11.84% respectively. The AquaCrop model was evaluated for simulation of grain yield and biomass of Rabi maize for all treatment with the prediction statistics 0.971 < E < 0.988, 0.221 < RMSE < 0.731, 0.987 < R2 < 0.997 and 0.421 < MAE < 0.806 t ha-1. The AquaCrop model predictions for grain yield and biomass of Rabi maize were in line with the observed data corroborated with E and R2 values approaching one. The AquaCrop model was more accurate in predicting the Rabi maize yield under full and 75% of CI as compared to the Rainfed and 50% CI.