Abstract

Introduction: The agriculture sector is an important sector in all over the world, particularly in developing countries such as Iran. Also, this sector affected by many factors which climate is one of the important ones. Dust phenomenon is one of the consequences of climate change that affects various economic sectors, especially the agriculture sector. Khuzestan Province as a major field of agriculture in Iran increasingly faces this phenomenon. The purpose of this study is to estimate the effect of the dust phenomenon on alfalfa yield in Khuzestan province Material and methods: In this research, the yield function method was applied in order to estimate the effect of dust and climatic variables on alfalfa yield. Accordingly, the amount of alfalfa yield, considered as a function of different factors such as the number of hours of exposure to the dust, the climate, economic, social and infrastructure condition variables. In order to estimate the effect of the variables of the research, econometric panel data model was applied. Data is collected from 16 divisions of Khuzestan province during the years 1991 to 2016 from the various statistical sources such as Ministry of Agriculture-Jahad, Meteorological Organization and Statistics Center of Iran. Results and discussion: The results of the regression model show that most of the climate variables have a significant effect on alfalfa yield. In fact, except wind speed variable, which is found insignificant others like rainfall, temperature and humidity variables have a positive and significant effect on alfalfa yield; as per centimeter increases in annual rainfall, the alfalfa product grows 59.5 kg/hectare; with an increase of 1% average humidity, the alfalfa yield will increase by more than 230 kg/hectare; also, if the average temperature increases in a degree of Fahrenheit, yield will increase by more than 283 kg/hectare. In the meanwhile, the effect of the dust variable on the alfalfa yield is negative and significant. So, any increase in the dust phenomenon leads to decrease in alfalfa yield. As, an hour increase in the dust encountering hours, causing a decrease of more than 0.972 kg/hectare of alfalfa. It should be noted that the impact of infrastructure, mechanization, and farmer education variables on alfalfa yield was evaluated positive and significant. So, with an increase of one percent of the variables of infrastructure, mechanization and farmer education, the alfalfa yield increases by more than 41, 33 and 46 kg/hectare, respectively. Also, with the assumption of other conditions being constant, the yield of alfalfa during the study period increased by more than 170 kg/ hectare. Conclusion: Regarding the main objective of this study, which is to estimate the effect of dust on alfalfa yield in Khuzestan province, and according to the results of the study, yield of alfalfa is decreased by 564 kg/hectare annually. Based on this, it can be said that annual dust causes for loss of 1,663 tons of the production of alfalfa, which is equivalent to 5.7 percent of the province's total alfalfa yield. Considering the price of alfalfa 6929 Rials/kg in 2016, the annual income of Khuzestan farmers has decreased by 11.5 billion Rials in the mentioned year.