Author : Nath, Hiranya K.; Mandal, Raju

Summary : Understanding the nature and extent of climatic impacts on agricultural productivity under a variety of scenarios is extremely important for developing countries, where a sizable portion of the population relies on agriculture for life and livelihood. Thus, this paper presents evidence of heterogeneity in climatic impacts on crop yield in Assam, India. In particular, applying the non-parametric quantile regression technique to district-level data from 1978 to 2005, this study examined heterogeneity in the impacts of temperature and rainfall across seasonal rice varieties (autumn, winter, and summer), agroclimatic (AC) zones, and the distribution of rice yield. The results suggested that, in general, the effects of temperature on yield were not statistically significant for any of the three seasonal rice varieties. However, these effects were not uniform in their magnitudes, signs, and statistical significance across AC zones and yield distribution for each variety of rice. Similarly, there were wide variations in the effects of total precipitation across seasonal varieties, AC zones, and yield distribution. The results also suggested that an increase in temperature variability is beneficial and that rainfall variability is harmful to autumn and winter rice yield. For summer rice, the effects of these two climate variables were positive but statistically insignificant. Given the importance of rice yield for food security and poverty alleviation in Assam, these results could inform the design of appropriate adaptation strategies and public policies to counter the adverse impacts of climate change on agriculture in Assam. Furthermore, since most people in rural areas are engaged in agriculture, these results are important for the sustainability of rural economies.