Drought Risks And Adaptation Mesures Of Maize Production In Northeast China Under Climate Change

Drought is the largest limitation for maize production in the northeast farming region (NFR). In order to develop appropriate adaptation measures against drought, it is crutial to quantitatively evaluate drought risks in different maize growing season. A quantitative approach was used to evaluate the effects of adaptation measures against drought based on a set of farmer surveys and to assess the influences of factors on the determinants of farmer’s choice of adaptation measures against drought. The study forecasted the impacts of climate change on the cropping systems and investigated the priority of adaption measures across NFR in the future based on a set of expert survey. The major conclusions of the study are as follows:(1) Through analyzing historical climate data and crop production data for the period of1961to2010, the results indicated that the increase of mean temperature was beneficial for maize production in the seeding and maturity phases, while the increase of mean temperature would lead to higher heat stress in the vegetative and flowering phases thus led to maize yield loss. The increase of radiation in the vegetative and maturity phases was beneficial for maize yield. Drought has had significant impacts on maize yield in each maize growth phases in NFR, the statistic results indicated that0.1unit increase of water deficit in the seeding, vegetative, flowering and maturity phases would respectively lead to527.8,397.8,145.3and78.4kg/hm2of maize yield loss.1day increase of drought stress days in the seeding, flowering and maturity phases would respectively lead to56.1,58.7and21.2kg/hm2of maize yield loss. Irrigation can mitigate the negative effects of drought on maize yield,1mm increase of effective irrigation water in the seeding, vegetative, flowering and maturity phases would respectively lead to an increase of9.3,3.9,4.1and2.1kg/hm2of maize yield.(2) Based on farmer questionarie survey and field experiment research, adaptation strategies against drought in spring adopted by farmers in NFR include adopting various maize varieties, drought-resistant maize varieties, dibbling irrigation, changing sowing time, mulching and water conservation tillage measures. Adaptation strategies against drought in summer include using irrigation, organic fertilizer and deep irrigation. Adaptation strategies against drought in autumn mainly include irrigation. Our results indicated that maize area, irrigation conditions and drought forecast and technical support provided by the government were the major factors that affected farmers adopting adaptation measures against drought in spring. Irrigation conditions, drought forecast, drought relief subsidies and technical support were the major factors that affected farmers adopted adaptation measures against drought in summer and autumn. In2009, the use of various maize varieties can lead to an increase of155kg/hm^of maize yield, the use of drought resistant maize varieties can lead to an increase of173.0-180.8kg/hm2of maize yield. Comparing to traditional rotary tillage, the use of water conservation tillage can lead to an increase of604.5-639.3kg/hm2of maize yield, irrigation in summer and autumn can respectively lead to an increase of182.0-191.5and182.8-206.7kg/hm2of maize yield. Compared to rotary tillage, conservation tillage, such as no tillage and wide-narrow alternative tillage, could improve water conservation capacity, and increase water use efficiency, which will be a useful measure against drought in maize production across NFR.(3) Expert survey results indicated that drought, flooding, chilling damage, wind damage and hailstorm were the major agro-meteorological hazard that affected maize production in NFR. The expected climate change will extend maize growing season in the future in NFR, global warming will be beneficial for maize sowing and harvest, the delay of late frost will mitigate the risk of chilling damage. Maize production will face with higher drought disaster and heat stress in NFR, climate change will also increase the risk of diseases, pests and weeds in maize production. Maize production in NFR in the future should invest more in breeding against climate change, agricultural infrastructure, optimizing cropping system, crop protection, seasonal weather forecast and using of machinery to cope better with climate change.