Study On The Calculation And Spatial Distribution Of Cultivated Land Fallow Scale In Ecological Degradation Area Based On The Perspective Of Ecological Security

The system of cultivated land rotation and fallow is one of the important strategic measures of cultivated land protection and utilization transformation in China.It is also an important system to improve the land capacity,improve the ecological environment of cultivated land,and realize the storage of grain in the land.The ecological environment of cultivated land will have an important impact on regional or national food security.Under the strategic background of sustainable development,it has become an important part of national ecological security strategic deployment.It is a major deployment made by the Party Central Committee and the State Council to carry out the experiment of rotation and fallow system.Its purpose is to promote the fallow of cultivated land and to ensure the food security and sustainable development of social economy.From the perspective of ecological security,implement the rotation fallow system,through the diagnosis and identification of the vulnerability of cultivated land in the ecological degradation area,predict the scale of the implementation of rotation fallow land in the future,and make it realize reasonable allocation in space,which is conducive to the control of regional cultivated land status and human land relationship,complete the important task of protecting agricultural ecology,and promote resource-saving and environment-friendly society To speed up the construction of green planting system with Chinese characteristics.From the perspective of ecological security,based on the review of the research progress of cultivated land fallow scale and spatial distribution at home and abroad,and guided by the theories of land ecology,human land relationship and sustainable development,this paper establishes the research path of "diagnosis of fallow area,prediction of fallow scale,optimization of fallow land distribution",and advances the implementation of fallow system in the ecological degradation area of cultivated land Conduct discussion.On this basis,Qingyang County,which is located in the northwest ecological degradation area and one of the first pilot areas of cultivated land fallow in China,is selected as the research area to diagnose the ecological vulnerability of cultivated land,identify the spatial distribution of cultivated land that needs fallow;predict the cultivated land scale that can be used for fallow in the future with the prediction of cultivated land conservation as the constraint condition of fallow scale;and According to the scale of fallow and the urgency level of fallow based on ecological vulnerability assessment,the priority fallow land and the follow-up fallow land are arranged to land orderly;the countermeasures and suggestions to promote the implementation of fallow land in the ecological degradation area are put forward.The main conclusions of this paper are as follows:(1)The cultivated land fallow in the northwest ecological degradation area is a new requirement of national ecological civilization construction for the utilization of cultivated land.The prediction of fallow scale and spatial arrangement should mainly focus on ecological security.From the perspective of regional cultivated land ecological security,based on the classification of cultivated land ecological vulnerability level,combined with a certain rate of food self-sufficiency and per capita cultivated land area,the scale of arable land can be calculated and put into space according to the ecological vulnerability level,which is a feasible path for the spatial layout of cultivated land in ecological degradation area.(2)The ecological fragility of cultivated land in Huanxian county is strong,and the ecological degradation of cultivated land is obvious.The comprehensive vulnerability score of cultivated land ecosystem in Huanxian county is between 0.297 and 0.6228.According to the equal distance method,the vulnerability of cultivated land is divided into four types: extremely vulnerable,very vulnerable,relatively vulnerable,and generally vulnerable.Among them,the very vulnerable cultivated land accounts for 46.38% of the total area of cultivated land,the general vulnerable cultivated land accounts for 53.04% of the total area of cultivated land,and only lessthan 1% of the cultivated land is in the general vulnerable state.(3)Under the restriction of cultivated land demand target,the characteristics of spatial agglomeration of cultivated land in Huanxian county are obvious.From 2015 to 2020,the total arable land in the county is 164900.01hm~2,accounting for 72.07%of the total arable land in the county.There are 35385 plots(plots)of arable land,which are semi enclosed in space.Through the three fallow lines designed in this paper,the fallow scale can be divided into three parts: the west,the north and the south,mainly involving the township with lanes,Hongde Township and the surrounding towns,Maojing Township,Nanqiu Township,Shancheng Township,Tianchi Township,Tianshui Town,etc.(4)In the future,the fallow land in Huanxian county can be landed orderly according to different levels of fallow scale and corresponding fallow level types.According to the actual distribution of fallow farmland in Huanxian County,combined with the layout experience of land remediation projects,and based on the principle of maximizing the benefit of fallow implementation,the fallow farmland in Huanxian county is divided into two levels: priority fallow and reserve fallow,which correspond to two fallow levels respectively.According to the urgency of fallow,they are suitable fallow,more suitable fallow and less suitable Fallow and unsuitable fallow.(5)The fragile ecological environment of cultivated land in the ecological degradation area of Northwest China determines the particularity of cultivated land utilization conditions.The first is to reduce the ecological environment load of cultivated land from the improvement of cultivated land conservation and management and utilization conditions;the second is to strengthen the ecological protection of cultivated land,actively encourage farmers to participate in the ecological protection of cultivated land,play their subjective initiative,and promote the restoration of the ecological environment of cultivated land.