Evaluation of Maize yield and Water Footprint Variability by AquaCrop-GIS Model

Estimation of the production potential of a crop is a function of climatic conditions, crop genetic potentials and various other environmental and managerial factors. Assessing the ability of regions to realize the genetic potential of crops is one of the important points of macro-planning in agriculture. Considering the position of Qazvin province in the production of Maize and the importance of cultivating this crop, estimating the yield of this strategic product as accurately as possible is very necessary. In this regard, by studying an 11-year statistical period, Maize yield was estimated with the new crop model AquaCrop-GIS. The zoning of key product indicators was simulated through the model in the province. By examining the results of these parameters, it finds that Qazvin and Moallem Kelayeh study stations with higher reference evapotranspiration rates have higher water productivity. Then, with the help of the computational yield, components of water footprints, and total water footprint of the crop was estimated within the study stations. By examining the regression equations in each station, it was found that the relationship between blue water footprint and crop yield compared to other water footprint components for all stations has a higher coefficient of determination (R2 = 0.43, R2 = 0.51, R2 = 0.43, R2 = 0.77 and R2 = 0.79 for Qazvin, Avaj, Moallem Kelayeh, Takestan and Buin Zahra stations, respectively) and level of significance. In general, the coefficient of determination of these relationships in Buin Zahra station with R2 = 0.88, R2 = 0.79, R2 = 0.56 and, R2 = 0.53, respectively, for green, blue, gray, and total water footprints compared to other stations were rated higher. This reduction in yield at the station had a significant effect on increasing the total water footprint of the crop.