ENSO, climate variability and crop yields in China

Abstract

The El Nino-Southern Oscillation (ENSO) is one of the most important contributors to global interannual climate variability, but the relationship between seasonal climate and crop yield variations associated with ENSO in China remains inconclusive. In this study, we investigated the impacts of ENSO on the yield of 3 staple crops (rice, wheat, and corn) at the provincial scale. We found that ENSO has significant impacts on wheat yields throughout China, and on rice and corn yields in major production areas. Specifically, more (less) rainfall during the wheat growing season in El Nino (La Nina) years leads to increases (decreases) in wheat yield, especially in southeastern China. Increases (decreases) in rice yield in northeastern China are due to warming (cooling) in El Nino (La Nina)years. In southern China, the variability of rainfall plays a more important role in rice yield than that in northern China. Corn yields in northern China are significantly affected by ENSO-induced changes in maximum temperature, solar radiation, and rainfall. Moreover, all of the staple crop yields are highly correlated with the ENSO index with a lead of at least 6 mo. For rice and corn in many provinces, the yields are typically most correlated with the index of the spring season during the ENSO developing years, suggesting that such yields can be predicted 1 yr before the growing season. The large variability in seasonal climate and agricultural production associated with ENSO warrants the application of ENSO information to food market management in China