Identification of climatic and management factors influencing wheat’s yield variability using AgMERRA dataset and DSSAT model across a temperate region

One of the main challenges of today’s agriculture to ensure food security is developing strategies to deal with potential negative impacts of adaptation to climate variability. This study was conducted to determine climatic and management factors influencing wheat yield variability throughout a temperate region in Northeastern Iran in the period of 1980–2010. The growth stages and yield of wheat crop were simulated via DSSAT model, using AgMERRA gridded weather dataset. Also, the effect of climatic variables on yield was identified using Panel Data Regression (PDA). According to the results, 63% of the changes in irrigated wheat yield are explained by climatic factors (temperature and precipitation) and 37% by management factors. PDA revealed that among the climatic variables, the number of days with temperatures above 30 °C during the growing season, mean temperature, as well as amount and frequency of precipitation have a significant effect on irrigated wheat yield (p ≤ 0.05). The management practices, including provision of inputs such as chemical fertilizers, modified seeds, tillage machinery and equipment, information transfer and the penetration of knowledge in the field, would increase yields by 5 kg on average per year in study region. In general, employing effective management methods, in particular selecting the appropriate planting date that could result in better adaptation of the phenological stages of wheat to climatic conditions, thus improving the wheat yield. The results of this research suggest that use of valid AgMERRA meteorological dataset as input for DSSAT crop model could produce reliable simulations which in turn could be employed by food policy and decision makers, farmers, and managers in a temperate region.