Heterogenous response of rice yield to climate factors: a Just-Pope stochastic production function and quantile regression analysis

Many studies have examined the average and non-linear effects of climate on crop yield, but limited research have further investigated the potential heterogeneity of climate effects induced by heterogenous land quality, which reduces the efficiency of climate change adaptation. This study is devoted to capturing heterogenous impact of climate factors on rice yield during different rice growing periods using a Just-Pope model and quantile regression approach. The results show that (1) in the mean function, both accumulated temperature and precipitation have significant non-linear effects on rice yield, and the impacts vary significantly at three different growing stages; (2) in the variance function, accumulated heat has an inverted U-shaped effect on rice yield variability during the seedings period and maturing period, while precipitation has an insignificant impact; and (3) accumulated heat shows a strong heterogenous effect on rice yield across nine quantile groups, with the effect being stronger at higher quantiles. Conversely, precipitation shows a relatively homogenous effect across different quantiles. (4) In addition to climate factors, we also find significant and heterogenous effects of fertilizer input and rice policy on rice yield. This study highlights the importance of developing climate change adaptation strategies and practices based on the heterogeneous effects of rice yield quantile groups to climate change in different crop growing stages.