Study On Cultivated Land Quality Enhance Potential Based On Limiting Factors

Cultivatedlandresources asa material carrierofagricultural production,which was an important basis for the development of national economy.With the accelerating pace of urbanization,the sharp decline in the number of cultivated land,the trend of quality decline intensified,food security issues continue to highlight the contradiction between people increasingly prominent.In the case of a limited number of cultivatedland,to improve the quality of cultivated land,and tap the potential of cultivated land was the key to the sustainable use of arable land.Therefore,this paper,with the guidance of agricultural land classification theory and the existing cultivated land data,evaluated the current situation of cultivated land quality in Shifang City in 2014.The restrictive index model was used to calculate the restrictive index of cultivated land quality limiting factor,and the limit degree of different limiting factors was analyzed.Using ArcGIS10.3 software to analyze the factors of cultivated land constraints,and to identify the main limiting factors,then divided the city's arable land into the recent,medium and long-term quality to enhance of district.On this basis,the potential of the quality of cultivated land in different quality promotion area was estimated,and the city's cultivated land quality improvement potential size was analyzed.Finally arable land quality construction direction and recommendationswere proposed combination of the actual construction.The main conclusions of this paper were as follows:(1)The quality of cultivated land was different and the geographical distribution was obviousIn 2014,the physical quality grade of the cultivated land of Shifang City distribution range between 7 grade and 10 grade.The highest level of cultivated land which the physical quality grade is 7 grade range of distribution was wide,followed by the cultivated land which the physical quality grade is 8 grade and 9 grade,and the area of the cultivated land which the physical quality grade is 10 grade was the least,which accounting for 75.62%,14.79%,8.58% and 1.01% of the total area of cultivated land in the city respectively.Higher cultivated land was concentrated in the southern plains,low cultivated land distribution in the northern hills and low valleys in the southern valley.(2)The degree of limiting factor mainly was in the middle,the proportion of cultivated land by multi-factor common to limit was bigFrom the analysis of the degree of limiting,the range of pH limits was wide,and the degree of restriction was moderate and distributed in the southern plains.In the north hilly area,the slope limit and irrigation limit were the main ones,and the restriction degree was high.The low-lying area of the southern valley was dominated by profile configuration,and the degree of restriction was high.From the perspective of the dominant restrictive factors,the proportion of arable land restricted by multiple factors was 50.47%,which was dominated by "organic matter-acidity".On this basis,the proportion of cultivated land in the near,medium and long-term areas was 22.38%,63.22% and 14.40% respectively.(3)There were differences in the timing and space of potential of cultivated land quality improvement,and comprehensive promotion potentialLong-term quality promotion zone had the greatest potential,medium-term quality improvement zone potential had the second,and the recent quality promotion area had the smallest potential.The potential of the recent quality improvement zone was between 0 grade and 1 grade,and the area of cultivated land which can be raised by 1 grade accounted for 6.18% of the total area of the quality improvement area,mainly from 9 grade to 8 grade.The potential of the medium-term quality improvement area was between 0 grade and 1 grade,and the area of cultivated land,which can be raised by 1 grade,accounts for 10.05% of the total area of the quality improvement area.The potential of the forward quality upgrading zone was between 0 grade and 2 grade,and the area of cultivated land which can increase the area of cultivated area was 94.75% of the total area of the quality improvement area,mainly from 8 grade to 7 grade.Cultivated areawhich can be raised by 1 grade,accounts for 0.35% of the total area of the quality improvement area.In general,the potential of large cultivated land concentrated in the northern hilly areas and low valleys in the southern region.After the leading limiting factors have been improved,the physical quality grade which of the cultivated land of Shifang City distribution range between 7 grade and 9 grade.The 7 grade of the cultivated land increased by 13.23%,the 8 grade of the cultivated land and the 9 grade of the cultivated reduce the proportion of 5.96%,6.26%.(4)According to the potential of different quality improvement area,combined with local practice,the construction and development of cultivated land quality in Shifang City has provided concrete directions and suggestions.Land remediation,combined with remediation project on the recent,medium and long-term quality of Shifang City put forward specific remediation projects and measures to improve the use of the level,from the increase in farmland investment and strengthen the scale of operation to start;optimize the basic farmland layout,according to the recent,medium and long-term quality improvement potential,can provide a direction for the basic farmland layout reference.