Factors Creating Systematic Risk for Rainfed Wheat Production in Iran, Using Spatial Econometric Approach

In this study, the factors creating systematic risk for dry farming wheat crop in Iran were investigated. Using production functions as well as spatial econometric approach, the effects of changes in climatic parameters such as temperature and precipitation, and also input levels of seed, urea, and phosphate fertilizers in warm, moderate, and cold climates were examined. The results showed that the fluctuations of climatic parameters in the three climates were severe enough to be identified as systematic risk factors. The findings also indicated that, in a warm climate, lack of sufficient heat during cultivation time (October), overheating during initial growth months (December and January), lack of sufficient precipitation during initial growth months (November and December) and inadequate seed and urea fertilizer and overusing phosphate fertilizer were the systematic risk factors. In moderate climate, these factors included lack of sufficient heat in cultivation time (October) and in late harvest time (July), lack of sufficient precipitation in the cultivation time (October) and lack of urea fertilizer and seed phosphate overuse. Finally, in the cold climate, insufficient heat in vegetative growth time (March), inadequate precipitation in the cultivation and initial growth time (October and December), and also lack of phosphate fertilizer and seed overuse were identified as the systematic risk factors.