A Study On The Spatio-Temporal Variation,Driving Factors And Recoverability Of "Non-Agriculturalization" And "Non-Grain" Cultivated Land In Guangxi

The"non-agriculturalization"and"non-grain"of cultivated lands affect the quantity,quality and ecology of cultivated land in China,which is related to national food security and long-term stability.Analyzing the evolution process of"non-agriculturalization"and"non-grain"cultivated land and its main influencing factors,and evaluating its recoverability are the basis for systematically managing the"non-agriculturalization"and"non-grain"cultivated lands and implementing the strategy of storing grain in the land.According to the data of the third land survey in Guangxi,the phenomenon of"non-agriculturalization"and"non-grain"cultivated land in Guangxi is prominent,but its spatial and temporal variation characteristics,driving mechanism and recoverability are unknown.Based on the land use data from 1980 to 2020,using GIS spatial analysis method,standard deviation ellipse model,hotspot analysis,k-means clustering and other mathematical models and methods,the spatial and temporal evolution characteristics of"non-agriculturalization"and"non-grain"cultivated lands were described.Thirty-five natural and social factors were selected from the aspects of site conditions,social and economic development level and agricultural development status,and the main driving factors of"non-agriculturalization"and"non-grain"cultivated lands were identified by using geographical detectors.Focusing on the suitability of tillage and the transfer path of cultivated land,the recoverability of"non-agriculturalization"and"non-grain"cultivated land was quantitatively evaluated.The main results are as follows:(1)From 1980 to 2020,the area of"non-agricultural"cultivated land in Guangxi showed a trend of fluctuating growth.The dynamic degree of cultivated land increased with time,and the area of cultivated land used stably decreased by 24,000 km~2.From the perspective of the transfer direction of"non-agricultural"cultivated land,the transfer of cultivated land mainly occurs between forest land,urban and rural construction land and grassland.The regional characteristics of"non-agricultural"cultivated land in Guangxi are obvious,mainly distributed in the southern part of southern and central Guangxi.The center of gravity and hotspots of"non-agricultural"cultivated land are located in southern Guangxi,which deviates from the center of gravity of geographical geometry and has strong spatial heterogeneity.The trajectory of the center of gravity is tortuous,showing a"northeast-southwest"two-way circuitous.(2)From 2000 to 2020,the sown area of crops in Guangxi decreased by 0.15 million km~2,and the sown area of non-grain crops increased by 22%.The planting structure of crops showed a trend of"grain retreat and economic advance",in which vegetables and sugarcane were the dominant"non-grain"crops in Guangxi.In 2020,the area of"non-grain"in Guangxi will reach 32,400 km~2,accounting for 57.04%of the total cultivated land area,and the problem of cultivated land non-grain is serious.At the same time,the degree of"non-grain"cultivated land in each county is deepening,and the number of counties with extremely high"non-grain"rates is increasing.Spatially,the hotspots of"non-grain"cultivated land are concentrated in the southwest of southern Guangxi;the center of gravity is mainly located in the south of central Guangxi,and the overall center of gravity moved 26.05 km to the southwest during the study period.It shows that the southwest of Guangxi is the concentrated area of"non-grain"cultivated land,and the spatial agglomeration is gradually increasing,which should be the key monitoring area of"non-grain"cultivated land remediation.(3)The main factors driving the"non-agriculturalization"and"non-grain"of cultivated land in Guangxi are different.Affected by the level of social and economic development(GDP,per capita net income of farmers,investment in fixed assets,proportion of construction land,total power of agricultural machinery)and regional farming conditions(landform type,proportion of ecological land,field regularity GS,field aggregation,slope),cultivated land tends to"non-agriculturalization",of which GDP and field regularity GS are the main influencing factors.Affected by site conditions(multiple cropping index,field aggregation,soil alkali-hydrolyzable nitrogen content,slope,altitude,annual average temperature,annual precipitation,grain sown area)and regional economic development level(effective irrigation area,total power of agricultural machinery,proportion of regional primary industry output value,regional GDP),cultivated land will tend to be"non-grain",among which the proportion of regional primary industry output value and effective irrigation area are the main influencing factors.(4)In the past ten years,the recoverable area of"non-agriculturalization"and"non-grain"cultivated lands in Guangxi was 1903.13 km~2,and the cultivated land areas that could be preferentially restored and difficult to restore were 671.35 km~2 and 69.82 km~2,respectively.In space,a small amount of cultivated land that can be preferentially restored is mainly distributed in the south of central Guangxi and the east of southern Guangxi,and the cultivated land that is extremely difficult and difficult to restore is mainly distributed in western Guangxi.