Determination of Water Productivity in Grain Maize (KSC 706) using AquaCrop model in Kermanshah Province

Among the indicators of optimizing water consumption in the agricultural sector; crop water productivity index has received more attention. This index is estimated based on the crop yield and water requirement, which depends on meteorological parameters, soil characteristics, field management and crop type. Due to changes in meteorological parameters in different regions, changes in the crop yield and water requirement in different regions can be expected. In this study, the Maize SC 706 was cultivated in the research farm of faculty of agriculture, Razi University, Kermanshah, in a randomized complete block design with treatments of 120, 100, 80 and 60% of irrigation requirement and three replications. The AquaCrop model was calibrated and validated using measured farm data. The results of model output and field data showed that the difference between biomass yield and grain yield in irrigation treatments was significant at the level of one percent. According to the calibrated crop file and daily meteorological data (1988-2017), water requirement and grain yield under full irrigation conditions in five synoptic stations of Kermanshah, Islam Abad Gharb, Sarpol-e Zahab, Ravansar and Kangavar were estimated using the model. The average of grain yield for the 30 years studied in these stations was estimated at 9403, 9261, 9171, 9016 and 9151 kg / ha, respectively. According to the estimated yield and water requirement, the amount of water productivity in the full irrigation conditions was calculated, the amount of which for Kermanshah, Islamabad Gharb, Sarpol Zahab, Ravansar and Kangavar stations respectively were 0.95, 1.09, 1.09, 0.88 and 1.18 kg of grain per cubic meter of water were estimated.