Estimating crop water deficit during maize potential growth period and climatic sensitivity analysis in Northeast China, 1961–2010

SUMMARYOne of the probable adverse effects of climate change on agriculture is yield loss due to water scarcity. Assessment of meteorological drought risk with the index of crop water deficit (CWD) can help in determining appropriate adaptation strategies to counter such losses. Using daily weather data from 68 stations in Northeast China (NEC) for 1961–2010, the spatial and temporal behaviour ofCWDwas assessed and the sensitivity of climatic variables related toCWDduring the potential growth period of maize was explored. The results indicated that the potential maize growth period decreased by 26 days due to climate warming. The deficit (i.e. a negative value for water demand) decreased from east to west and decreased gradually during 1978–1984 and sharply during 2000–2010. It is noteworthy that NEC experienced severe droughts especially in the 1970s and the 2000s, and relative humidity was the most sensitive parameter affecting evapotranspiration. Regions in the middle of Heilongjiang and Jilin should take precautions concerning climate change effects onCWD, while the northern part of NEC should take precautions concerning changes in temperature and sunshine hours. Growing late-maturing and drought-tolerant maize varieties is therefore a good option for higher production in NEC, coupled with enhancing the availability of water in this limited-rainfall region, and should form a part of the strategy to cope with climate change.