Study On Productivity Calculation And Carrying Capacity Of Cultivated Land In Loess Region Of China

Ensuring the quantity and quality of cultivated land has a vital impact on food security,ecological security,social stability and economic development.As a typical soil type in the loess plateau region,there is a lack of in-depth research on the macro comprehensive characteristics and productivity potential of loess soil.Loess soil through quantitative calculation of the cultivated land area capacity,evaluate its carrying capacity,size analysis of cultivated land productivity and spatial distribution law of bearing potential,to increase the per unit area yield of yellow spongy soils area of cultivated land and the national reserves and reserve cultivated land resources has important guiding significance to the quality,for the regional agricultural production and national spatial planning to provide theoretical support.Based on resource scarcity theory,land production theory,system theory and other theories,this study used local thin film spline function method,Kriging interpolation method,potential attenuation method,GIS spatial analysis and other methods.The temporal and spatial distribution of climate,productivity,utilization potential,utilization intensity and carrying potential of cultivated land in Loess soil area from 2000 to2016 were quantitatively analyzed.The results are as follows:(1)In 2000,the theoretical yield per unit area was 1257kg/ mu,the realized yield per unit area was 512 kg/ mu,and the actual yield per unit area was 286 kg/ mu;The theoretical capacity of cultivated land in Loess soil area is 64.1010 million tons,the realized capacity is 26.9605 million tons,and the actual capacity is 14.2355 million tons.The theoretical potential utilization of cultivated land was 37.1405 million tons,and the realized potential utilization was 12.725 million tons.The theoretical utilization strength is42.06%,and the realized utilization strength is 52.80%.In 2016,the theoretical yield per unit area of loess soil was 1494kg/ mu,the realized yield per unit area was 673 kg/ mu,and the actual yield per unit area was 455 kg/ mu.The theoretical capacity of cultivated land in Loess soil area is 75.2355 million tons,the realized capacity is 33.2669 million tons,and the actual capacity is 22.832 million tons.The theoretical potential utilization of cultivated land was 41.9686 million tons,and the realized potential utilization was 10.4343 million tons.The theoretical utilization intensity was 44.22%,and the realized utilization intensity was 68.63%.(2)From the perspective of space,the distribution trend of arable land productivity in2000 and 2016 was similar.The theoretical yield per unit area,achievable yield per unit area and actual yield per unit area decreased gradually from southeast to northwest,which was higher in the southeast,followed by the middle and lower in the northwest.Theoretical capacity,realizable capacity and actual capacity gradually decreased from southeast to northwest,which was higher in the south and northeast,followed by the middle,and lower in the northwest and north.The utilization potential showed a decreasing trend from southeast to northwest,which was higher in southeast and lower in northwest.Theoretical utilization intensity showed a decreasing trend from southeast to northwest,which was higher in southeast and lower in southwest and northeast.The utilization intensity can be reduced from northwest to southeast,which is higher in northwest and lower in southeast.(3)In 2000,the theoretical carrying capacity of cultivated land in Loess region was128.2 million,the realized carrying capacity was 53.92 million,and the actual carrying capacity was 28.47 million;The theoretical carrying capacity density is 2.60 persons/mu,the realized carrying capacity density is 1.10 persons/mu,and the actual carrying capacity density is 0.58 persons/mu.In 2016,the theoretical carrying capacity of cultivated land in Loess soil region was 150,470,000,the realized carrying capacity was 66.53 million,and the actual carrying capacity was 45.66 million.The theoretical carrying capacity density is3.06 persons/mu,the realized carrying capacity density is 1.35 persons/mu,and the actual carrying capacity density is 0.93 persons/mu.(4)The counties with high carrying capacity of loess soil are located in central and northern Shaanxi,western Shanxi,southern Ningxia,and southern and eastern Gansu.The counties with low carrying capacity are surrounded by the counties with high carrying capacity.The theoretical capacity density and the realized capacity density decrease from southeast to northwest,and the density is larger in southeast,followed by the middle,and smaller in northwest.The actual carrying capacity density showed a tendency of high density in the central part and low density in the eastern and western parts.The conclusion is that from 2000 to 2016,the yield per unit area and productivity of cultivated land at all levels in loess soil area have increased,the utilization potential of loess soil is large,the utilization intensity has room for improvement,and the carrying capacity and carrying capacity density of cultivated land in Loess soil area have also increased.From the perspective of space,loess soil is widely distributed,and there are great differences in natural and social economic conditions.Therefore,there are great differences in productivity and utilization capacity.From 2000 to 2016,the spatial distribution of theoretical carrying potential,realizable carrying capacity and actual carrying capacity at each county level in loess-soil region had the characteristics of aggregation.