Research Of Maize Production Changes In China At A Global Warming Of 1.5℃&2.0℃

The impact of climate change on food production has drawn widespread attention,accurately quantifying the response of major crops to climate change is the basis for understanding the impact of climate change on China’s agricultural production and food seccurity.The Paris Agreement has proposed to limit the increase in average temperature to less than 2℃before industrialization and strives to limit it to 1.5℃.Therefore,it is of great significance to accurately quantify the changes of maize production under conditions of global warming.This paper uses long-term serial record data of agricultural measure stations to,climate data,and soil data combined with the crop growth model DSSAT to comprehensively evaluate the temporal and spatial distributions of maize phenology,yield,ET,and WUE changes under the background of climate change in the main maize production areas of China.Prediction the changes of maize production in China under the predicted warming of 1.5℃ and 2℃.It is of important guiding significance to study maize growth in response to climate change,can be used as a reference for the adjustment of national planting structure.Mainly get the following conclusions:(1)Global warming of 1.5℃,the flowering period of maize will be generally ahead,the flowering date at Northwest Inland mazie zone,most part of the hilly maize zone in southwest mountainous regions and Inner Mongolia,Jilin and Liaoning provinces will advance 0 to 6 days.The days ahead of flowering date in Central Inner Mongolia,Heilongjiang Province and southern Jilin Province will reach 12-48 days.When global warming 2℃,the test of maize production in China will be more severe,compared with the warming of 1.5℃,the flowering date of maize showed a more obvious advancement trend,and the area where the flowering period showed an early trend further expanded.(2)The effect of global warming on maturity date of maize is different with it on flowering date,regardless of whether it is warming 1.5℃ or 2℃,the flowering date of maize were all advanced.However,global warming at 2℃ advances maize maturation in some areas,also other areas are postponed.This has a certain relationship with local irrigation levels and human management measures.(3)With a global warming of 1.50C,the areas where China’s maize production tends to decrease are mainly distributed in the western part of the northern spring maize zone,Liaoning Province,and central Jilin Province.The spring and summer sown maize region of Huanghuai Plain will face a significant reduction in production.When Warming 2 ℃,maize production in China will be further reduced,including the Huang-Huai Plain spring and summer sowing in most parts of the maize area will reach more than 50%,or even more.(4)Global warming 1.5℃,ET in maize growing season in most regions of China shows a decreasing trend,the possible causes are the decrease of solar radiation caused by the increase of pollutants such as cloudiness and aerosols in the atmosphere.ET changes show consistency across regions in global warming 2℃ and warming 1.5℃.However,the ET in the middle of the maize growing season in the spring and summer Huanghuai Plain maize zone has increased from a declining trend of 1.5℃ to an increasing trend.(5)Global warming of 1.5℃,WUE of maize in most regions of China shows an increasing trend,However,during the growing season of Huanghuai Plain spring and summer maize zone,WUE will decrease at a rate of 0～30%and show a pattern of increasing from east to west.Warming at 2℃,the WUE in the corn growing season will show a decreasing trend.The Huanghuai Plain spring and summer maize zone will spread from the eastern part of the Huanghuai Plain under the scenario of warming 1.5℃ to the entire spring and summer sown maize area in the Huanghuai Plain,even further expanding to the most of the western spring maize zone.(6)In the future,we must strictly control the global warming,at the same time,reasonably regulate interregional maize cultivation strategies.Global warming of 1.5℃ and 2℃,the trend of reduction in production in some areas such as the spring maize region in the north of China,Liaoning,Jilin,the Huanghei-Huai plain spring and summer maize area,as well as the southwest mountainous hilly maize zone,Therefore,in order to do a good defensive measure,the planting structure can be properly adjusted to minimize agricultural losses and increasing farmers’ income.