Danjiangkou Cultivated Land Quality Evaluation And Obstacle Factor Type Zoning Research

The reduction of China’s arable land resources and the decline in quality have seriously threatened our country’s food security.In order to understand the quality of cultivated land in detail and improve the quality of cultivated land,we need to investigate and evaluate the quality of cultivated land based on obstacles to provide a basis for the regional utilization and protection of cultivated land resources.This paper takes the quality of cultivated land in Danjiangkou in 2018 as the research object,and uses the Delphi method and the analytic hierarchy process to determine the weight and degree of membership of each indicator.At the same time,this paper uses fuzzy mathematics,qualitative and quantitative methods to comprehensively evaluate the quality of cultivated land in Danjiangkou.The obstacle degree model is introduced to diagnose the obstacle degree of indicators that affect the quality of cultivated land.After that,this paper delineates the cultivated land quality obstacle type area and the cultivated land quality improvement area,and finally proposes suitable cultivated land quality improvement suggestions for different obstacle factor types.The research results are as follows:(1)The total area of arable land in Danjiangkou is 30,435 hectares.The quality of arable land can be divided into 9 grades,ranging from grade 1 to grade 9.Danjiangkou cultivated land quality grades show significant agglomeration,mainly distributed in three grades of grade 4,grade 5 and grade 6.The total area of these three grades is 24356.03 hectares,accounting for 80%of the cultivated land area in Danjiangkou.Among them,the grade 5 arable land area is the widest,with 10204.58 hectares,accounting for 33.53%of the total arable land area.(2)Danjiangkou cultivated land quality grades present a staggered spatial pattern,mainly showing a trend of higher grades in the north and lower grades in the south.This is because the soil parent material and irrigation conditions in the northern part of Danjiangkou are good,the soil types are suitable for farming,the drainage capacity is strong,the biodiversity is rich,the degree of farmland forestry is high,the cleanliness is good,and the soil physical and chemical properties are excellent in all aspects.Through the autocorrelation analysis of the cultivated land in Danjiangkou,the local autocorrelation analysis of the comprehensive quality grade of the cultivated land is consistent with the comprehensive quality grade evaluation result of the cultivated land.(3)Based on the evaluation of the quality of cultivated land in Danjiangkou,the obstacle degree model is introduced to diagnose the obstacle degree of cultivated land.After that,the barrier factors are divided into barrier-free,mild harrier,moderate barrier and severe barrier.The results show that the main obstacles to the cultivated land in Danjiangkou are irrigation capacity,topography,organic matter,effective soil thickness,drainage capacity,available potassium,available phosphorus and biodiversity.The obstacles of the above obstacles decrease in order.(4)According to the diagnosis results of obstacle factors,rank the severe obstacle factors of cultivated land and screen out the main obstacle factors and secondary obstacle factors.Finally,5 categories and 14 types of cultivated land quality obstacle types were obtained.The five types of barriers are organic matter barriers,irrigation capacity barriers,terrain barriers,quick-acting potassium barriers,and effective soil thickness barriers.(5)Danjiangkou arable land resources and utilization conditions are different,and the technical measures that should be taken for each obstacle type area are also different.Put forward different countermeasures and suggestions for different regions to promote the improvement of cultivated land quality.In areas with organic matter barriers,we should pay attention to applying organic manure,planting green manure or returning straw to the field as effective measures to fertilize the soil and increase the yield of cultivated land;In areas with impediment to irrigation capacity,we should make full use of precipitation irrigation,use anti-seepage canals to transport water,supporting drip irrigation facilities,improve water-saving irrigation systems,and increase the effective utilization rate of irrigation water;In the area of the available potassium barrier type,it is adjusted by increasing the application of potassium fertilizer and cooperating with other organic fertilizers;In the effective soil thickness barrier type area,the effective soil thickness can be increased by breaking the plow bottom and the soil method;in the terrain type area,part of the area can be transformed by changing slopes to terraces.