| Since the global food crisis of 2007-2008,food security has remained a global challenge.Water loss and soil erosion,reduced ecological diversity,extreme weather changes,scarce land resources,deforestation,and agricultural environmental pollution are all common ecological and environmental problems facing countries.The destruction of the ecosystem first affects the natural environment.Among the human activities,the natural environment is closely related to agricultural activities.And food production occupies an important position in the entire agricultural field.In addition,food security is an important issue related to the national economy,the people’s livelihood,and the development of the national economy.The concept of sustainable agricultural development has emerged and been continuously improved in this context.Among the many indicators for measuring sustainable development,the ecological footprint method has been recognized and improved by many scholars at home and abroad since it was constructed.Therefore,studying the spatial and temporal changes of food production patterns and crop ecological footprint will be of great significance to food security.Northeast area is China’s most promising commodity grain base and an important grain production area,providing a large number of high-quality rations,feed grains and industrial grains for the country.In recent years,the center of gravity of China’s grain production has gradually shifted to the northeast,which further reflects the importance of the northeast region in China’s grain production structure.However,affected by the relationship between supply and demand and ecological benefits,its sustainable food production faces many problems and challenges.Therefore,the study of the spatiotemporal evolution of grain production and ecological footprint in the three northeastern provinces will be of great significance for optimizing the grain production structure and achieving sustainable production in China.This paper uses spatial autocorrelation global Moran index and hot spot analysis to explore the temporal evolution characteristics and spatial differences of grain production in the three northeastern provinces from 2000 to 2017.The evolution characteristics of time series change are described from three aspects of planting area change,yield change and structural change,and the spatial difference pattern is summarized from spatial agglomeration and spatial pattern.Based on this,8 indicators were selected from the aspects of agricultural input,technological level,economic environment,and market factors.The multiple linear regression model was used to explain the change in the proportion of crop sowing,and to analyze the influencing factors of the spatiotemporal evolution of grain production in the three northeastern provinces.In addition,based on the ecological footprint method,the crop ecological footprint(! "#)and !" $ were constructed.From the perspective of crop production ecological supply and demand,the ecological footprints of corn,rice,and soybean and ! "$ evaluation were studied and evaluated.In addition,this article divides the crop ecological footprint accounts of the three provinces in Northeast China,determines the calculation methods of related parameters,analyzes the characteristics of different crops,visualizes the crop ecological footprint of corn,rice,and soybean,and the !" $ and analyzes their changes.Concluded as follow:(1)From 2000 to 2017,the grain sown area and output of the three northeastern provinces continued to rise,and their status as the most promising commodity grain bases became increasingly apparent.Among them,the soybean planting area and yield both experienced the "rising-declining-rising" stage,which declined after 2009,2005 and 2008,respectively,and showed an upward trend in 2015.Corn planting area and yield showed a continuous growth trend,and the increase was large.The proportion of corn sown in Liaoning and Jilin provinces has always been higher than that of soybeans.The proportion of corn sown in Heilongjiang Province exceeded soybeans in 2010 to occupy the first place.Rice planting area and yield have steadily increased.Rice yield has always been higher than soybean yield.Its planting area surpassed soybeans to occupy the second place in 2011.The proportion of rice planting in Liaoning and Jilin provinces has always been higher than soybeans.Among them,the gap between the two in Liaoning Province widened after 2003,and the proportion of rice sown in Jilin Province grew relatively slowly,and the gap between the two was small.Heilongjiang Province’s rice sown percentage surpassed that of soybeans in 2011.It can be seen that corn and rice have gradually occupied the dominant position in grain cultivation,and soybean cultivation has a certain growth trend in the future.(2)Grain production in the three northeastern provinces has certain spatial distribution characteristics.The spatial agglomeration characteristics and changing trends of corn,rice,and soybeans are different.Among them,the most significant spatially concentrated crops are soybeans,followed by corn,and the least obvious is rice.The spatial changes and layout of cold and hot spots in corn planting are basically consistent with grain production.The hot spots are concentrated in the Songnen Plain,and the cold spots are distributed in the Liaodong Peninsula and northwestern Liaoning.The degree and scope of rice planting have changed greatly,and they have gone through the stage of "increasing degree,expanding range-decreasing degree,decreasing range".The spatial change of the hotspot area of soybean planting is the most obvious,and it gradually concentrated to the northwest of Heilongjiang.The concentration and scope of its cold spot area has been relatively large,concentrated in Liaoning Province and northern Jilin Province.The results of multiple linear regression analysis showed that the amount of fertilizer applied,the total power of agricultural machinery,the output value ratio of various crops and alternative crops,the proportion of output value of animal husbandry,the level of urbanization,and non-agricultural employment opportunities had significant effects on the cultivation of corn,rice,and soybeans.And through a certain impact mechanism,the three provinces of Northeast China have corresponding spatial layout of grain production.(3)The spatial change of !"# reflects the supply and demand status of crop production.The spatial change and distribution of the !"$ of corn,rice,and soybean crops are basically consistent with the changing trends and spatial distribution of their planting areas and yields.The !"$ of corn in most urban units has increased across types,especially in the Sanjiang Plain,Xiaoxinganling Mountains,Songnen Plain,and Changbai Mountains.The ecological condition of corn in the three provinces of Northeast China in 18 years has experienced the process that dominated by crop ecological surplus and then declining in the range of crop ecological surplus.The ecological deficit of rice in the Sanjiang Plain,northern Songnen Plain,and northern Changbai Mountains evolved into a surplus condition in 2009,and then developed into a balanced condition in 2017,the !"$ of rice has improved significantly.From 2000 to 2017,the !"$ of soybean showed an increasing trend that the ecological condition of soybean showed a certain degree of deterioration,and polarization became increasingly apparent.Based on this,the changes in the supply and demand balance status of the crop ecological carrying capacity in different regions of the three crops were analyzed in depth.Finally,the ideas and countermeasures for optimizing grain production input and production space layout in the three northeast provinces were proposed. |
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