Effect of short and long term climate variations on rainfed wheat yield in Kerman province

The aim of present study is to investigate the short and long-term effects of temperature and rainfall variations on rainfed wheat yield in Kerman province (Kerman station). For this purpose, time series data of these variables for the period of 1363-95 were retrieved and analyzed using the autoregressive distributed lag model (ARDL). The bounds testing confirmed the existence of cointegration and long-term significant relationships between climatic variables and the rainfed wheat yield. The long-term elasticity of temperature and rainfall in spring and winter were 1.71, 0.4, 0.36 and 1.52, respectively. Also, in case of the short term period, the correlation coefficients of spring rainfall, winter rainfall and winter temperature are 0.191, 0.169 and 0.611, respectively. Therefore, one percent increase in spring rainfall would cause approximately 0.19 % increase in yield. Similarly, one percent increase in winter rainfall leads to 0.16 percent increase in yield and one percent increase in winter temperature causes 0.61 percent increase in rainfed wheat yield. Based on these results, long term climatic variations are more responsible for overall observed yield trend. The coefficient of Error Correction Model (ECM) of the short-term variations is negative and significant at 99% level of confidence which confirms the long-term relationship between all model variables.