Evaluation Of Green Development Of Main Crops In Northwest China

This study takes the northwest region as the research object.The northwest region is located in the hinterland of the mainland.The agricultural ecological environment is fragile.The production status and food self-sufficiency rate of the main crops in the provinces of the northwest region from 2000 to 2019 were analyzed.The status of fertilizer use,the structure of fertilizer carbon emissions and the decoupling relationship between fertilizer carbon emissions and crop output value were analyzed in depth.The green development level evaluation system of the main crops in the northwest region was constructed to evaluate the green development of the main crops in the northwest region.The main results are as follows:From 2000 to 2019,with the gradual increase of total grain output in the northwest region,the grain self-sufficiency rate in the northwest region has been increasing.Since 2010,the grain in the northwest region has been fully self-sufficient.Among them,Xinjiang and Ningxia have always been grain export provinces,and the 20-year average self-sufficiency rates are138.9 % and 131.9 % respectively.There is a large grain gap in Shaanxi and Qinghai,and the20-year average self-sufficiency rates are 75.1 % and 44.2 % respectively.Gansu Province has achieved full self-sufficiency in grain since 2012,with an average self-sufficiency rate of 94 %in 20 years.In the past 20 years,maize and wheat were the main food crops in Northwest China,accounting for 46.1 % and 35.6 % of the total yield,respectively.Maize was mainly distributed in Xinjiang,Shaanxi and Gansu,accounting for 37.2 %,26.4 % and 25.8 % of the maize yield in Northwest China,respectively.Wheat is mainly distributed in Xinjiang and Shaanxi,accounting for 29.1 % and 43.8 % of wheat yield in Northwest China in 2019,respectively.Compared with 2000,the cotton production in Northwest China increased by3.4574 million tons in 2019,and the planting area increased by 1488.1 thousand hectares,of which the cotton planting area in Xinjiang increased by 1528.11 thousand hectares.Comparative advantage interval analysis of main crops,the dominant areas of wheat and maize are Shaanxi,Gansu and Qinghai provinces;the dominant area of rice is Ningxia Autonomous Region;the dominant area of cotton is Xinjiang Autonomous Region.From 2000 to 2019,the carbon emissions in the northwest region increased first and then decreased with time,reaching a peak in 2016.The carbon emissions of chemical fertilizers account for more than 50 % of the total emissions.The carbon emissions of chemical fertilizers for main crops in Northwest China also showed a trend of increasing first and then decreasing.The carbon emissions of nitrogen fertilizers and compound fertilizers accounted for more than90 % of the total carbon emissions of chemical fertilizers.The three provinces with the largest fertilizer emissions are Xinjiang,Shaanxi and Gansu.Among them,fertilizer carbon emissions in 2019 accounted for 42.1 %,36.0 % and 13.6 % of total fertilizer carbon emissions,respectively.The three crops with the largest fertilizer emissions are corn and cotton,wheat.Among them,the fertilizer carbon emissions of maize,cotton and wheat accounted for 35.3 %,33.4 % and 27.2 % of the total fertilizer carbon emissions of the main crops in 2019,respectively.Cotton fertilizer carbon emissions are mainly concentrated in Xinjiang,accounting for 98.1 % of cotton carbon emissions in the Northwestern China.In order to promote the reduction of agricultural carbon emissions in the northwest region,the future should focus on improving the fertilizer use efficiency of wheat,corn and cotton crops.The green development level of major crops in Northwest China is significantly different.In general,the order of green development level of main crops in Northwest China is rice >wheat > corn > rape > cotton.From 2008 to 2019,the green development level of cotton is far lower than that of other crops.The average relative proximity of green development of major crops in each province was analyzed.Xinjiang cotton was the closest to the ideal level,and Gansu cotton was the farthest from the ideal level.The order of obstacle degree in the green development of main crops in Northwest China is green production > economic benefit >resource utilization.Among them,rice,corn and cotton have the highest green production barriers;the economic benefit of wheat is the highest;the resource utilization obstacle of rape is the highest.The provinces in the northwest region need to make corresponding adjustments to the current shortcomings and restrictive factors of the main crops in the province.