Relationship between Climate Variables and Yield of Food Crops in Nepal : Cases of Makwanpur and Ilam District <Articles>

Agriculture, being sector largely dependent on climate variables, will be adversely affected by climate change. Therefore, this paper intends to assess how the recent trends of climate variables are affecting yields of major food crops in two hilly districts of Nepal namely, Makwanpur and Ilam based on district level data from 1978-2008. Trends of climate variables show that maximum and minimum temperature in summer as well as winter temperatures are increasing in Makwanpur, but in Ilam minimum temperature in both season shows declining trend. In case of rainfall, it is in increasing trend only during summer in Makwanpur. In all cases inter-annual variation of rainfall is very high. In contrast, crop yield shows some steady trends but in both directions; increase as well as decrease. For instance, except the yield of paddy and maize in Makwanpur, and maize and millet in Ilam all other food crops are in increasing trend. Among these food crops potato shows the highest rate of yield increase. Relating the trends of climate variables with yield of food crops shows that the current trend of minimum temperature has adversely affected yield of maize and paddy in Makwanpur, whereas in Ilam decreasing trend of rainfall has affected yield of paddy adversely. Despite the suppression of yield of these food crops by current trend of climate variables, most of these food crops overcame such suppression leading to the increase in overall yield. However, paddy, maize and millet are not able to overcome such suppression leading to decline in overall yield, thus requires special attention in order to cope with adverse effect of climate change in days to come.