Introduction
Changing in weather variables are considered as one of the most significant risks facing the agricultural sector, profoundly affecting the yield and price of agricultural products, especially rainfed crops. Farmers typically respond to these climatic and environmental changes by adjusting their cultivated area of these products, reflecting their most natural reaction. They align their production strategies with these alterations. Thus, it is crucial to analyze how climate factors influence risk and yield, particularly concerning rainfed wheat, chickpeas, and barley crops in Kurdistan Province, a key production hub for these crops. This analysis is essential for evaluating the risk-enhancing effects of these factors, similar to other provinces in the country. The aim of this study is to explore the acreage response of rainfed wheat, chickpeas, and barley crops in Kurdistan Province to changes in climate and prices.
Meterials and Methods
In the initial phase, the stochastic production function approach of Just and Pope was employed to analyze the effects of weather factor variations on the yield and yield risk of crop production, utilizing panel data estimation techniques that combine time-series and cross-sectional data from the counties of Bijar, Gharveh, Saghez, Kamyaran, and Divandarreh, which are crucial production areas for these crops. In the subsequent phase, under the framework of the von Neumann and Morgenstern expected utility function, the acreage response functions for these rainfed crops were estimated and analyzed using the seemingly unrelated regression (SURE) system. Climate data were collected from the meteorological stations in the five counties, while additional necessary data were sourced from the Agricultural Jihad Organization of the province, the Statistical Center of Iran, and the Central Bank, covering the period from 1987 to 2022.
Results and discussion
The study's findings indicated that factors such as precipitation, average minimum temperature, and average relative humidity during the growth period positively influence crop yields, while average maximum temperature and wind speed negatively affect the yields of the selected crops. The estimation results of the yield risk function revealed that cumulative precipitation during the growth period, average maximum temperature, average wind speed, and the interaction between average wind speed and average maximum temperature significantly impact the risk associated with rainfed wheat. For rainfed chickpeas, the yield risk function estimation results demonstrated that average maximum and minimum temperatures, average relative humidity, and average wind speed significantly influence the risk. Cumulative precipitation in the spring season, average wind speed in spring, average summer temperature, and average spring temperature have substantial effects on the risk for rainfed barley. The acreage response functions for these crops indicate that as expected profit rises, the cultivated area expands. Conversely, an increase in the variance of expected profit leads to a decrease in the cultivated area for each crop. Specifically, when profit volatility of rainfed wheat increases, it results in an expansion of the cultivated area for rainfed chickpeas, and similarly, an increase in rainfed wheat's expected profit variance also contributes to a rise in the cultivated area of rainfed barley, and vice versa.
Conclusions
As farmers’ wealth increases, the cultivated areas for wheat and chickpeas also expand. Consequently, wheat and chickpea farmers display decreasing absolute risk aversion, while barley farmers exhibit constant absolute risk aversion. Therefore, in environments of increased market risk, non-price policies aimed at expanding the cultivated area of barley and price-based policies for wheat and chickpeas can be effective.