Evaluation On The Effect Of Adaptation Countermeasures Of Maize On Climate Resources Utilization In Northeast China Under Climate Change

This study was based on recent domestic and international research progress on theeffects of climate change on agriculture, and the grid meteorological data for1981-2100fromRegCM3regional model in Northeast China were used to analyze the changing trends of theclimatic resources in Northeast China. Then, the variety distributions were further adjusted.In order to explore the effects of different adaptation countermeasures on climatic potentialproductivity and climate resources utilization in the future, the maize cultivars which couldbe resistant to high temperature, drought, and both high temperature and drought wereselected in this paper. The objective of this study was to explore patterns, evaluative rules,and impacts of different adaptation countermeasures on climatic potential productivity andclimate resources utilization under climate change. The key findings are:(1) From1980to2010, a significant increase was found in thermal resource. The firstdate when stably passing10℃was advanced, the final date was delayed, and theaccumulated temperature above10℃generally increased. However, high temperature heatwaves increased meanwhile. Water resources were fluctuant in the growing season. Theextreme precipitation mainly occured in the southern areas, and the extreme precipitation wasless in Heilongjiang province, which accounted a great part in the annual total rainfall.However, changes in precipitation were insufficient to offset the intensifications inatmospheric evaporation force caused by temperature increase, and the climate becamewarmer and dryer. At the same time, the radiation significantly increased in the growingseason which was benefit for the dry matter accumulation.(2) Due to the increasing accumulation temperature, the early-maturing varieties will begradually replaced by mid-late and late-maturing varieties in Northeast China. Thelate-maturing varieties canbe planted in most areas except the small part in northern Heihe ofHeilongjiang province during the year of2071-2100. Warming climate has negative effectson the maize production where thermal resources are sufficient. The climatic potentialproductivity will decrease in Liaoning province. While the climatic potential productivity willincrease in Jilin and Heilongjiang because of the extending days of growing period, and thehigh-value region will extend northward and eastward. The changes of climate will also bringchallenge for stable and high agricultural yield, and the amplitude of climatic potentialproductivity increases. It is an effective way to increase the climatic potential productivityand reduce the amplitude by variety adaptation countermeasures. The utilization of agricultural climatic resources will be obviously increased by variety adaptationcountermeasures with time. But the decline trend of climatic potential productivity will not bechanged.(3) The pertinent theory of fuzzy mathematics is applied to establish mathematicalmodels of the suitability. The average resource suitability index, average efficacy suitabilityindex, and average resource utilization index are defined to quantitatively evaluate the effectsof climate change on climatic resource utilization in Northeast China. The results show that:The average resource suitability index will decrease in the areas with sufficient heat resources,but it will increase in high latitude areas under climate warming, and the high value centerwill move northeast. The average efficacy suitability index will decrease because of the poorcoordination of climatic resources, and the average resource utilization index will be reducedas a result, the areas with low value will expand. The temperature suitability and watersuitability will be increased by planting resistant varieties which are favorable for theresources index. Water resource is the major constraint factor of grain yield under the futureclimate. Maize with drought resistance properties has great influence on the average efficacysuitability index, and the resources utilization will be increased. Breeding drought resistantvariety is an effective way to improve the efficient utilization of climatic resources.(4) According to the indexes of thermal resources and precipitation, the possibal changeof planting model is analyzed in Northeast China. The results show that: the northernboundary of two crops a year will extend northward and eastward, and the planting areas fortwo crops a year will increase. If the cropping system changes from one crop a year to twocrops a year in the sensitive areas, the growing season will be longer, and the climaticpotential productivity of winter wheat and summer maize will be higher than that of springmaize in Northeast China. However, the days of growing period for wheat and maize will beshortened in the areas where thermal resources are sufficient under climate warming, and thetotal climatic potential productivity will decrease there.