The Potential Of Stripping Tillage Layer Soil In Wangcheng District Of Changsha City For Upgrading The Medium And Low Yield Fields

Topsoil is the essence of the cultivated land and a non-renewable resources for agricultural production.In recent years,with the rapid development of economy in our country,the cultivated land used for construction has been increasing year by year and topsoil number is larger,but a large number of fertile topsoil,for the most part,not stripped.Waste of topsoil and huge pressure that construction must implement the“quality balance” in contrast.Based on Wangcheng District,by researching potential that middle-and-low-yielding fields use strippable topsoil of qualitative cultivated land,to explore a new ideas that realize the construction of cultivated land in Hunan Province dominant complement “quality balance”.In this paper,based land use planning(2006-2020)of Wangcheng District,farmland productivity level evaluation results data and so on,using GIS spatial analysis,to measure,evaluate and analyze the quantity,quality and distribution of topsoil occupied by construction;to measure,evaluate and analyze the quantity,quality and distribution of “Irrigation improved type”,“Waterlogging drainage type”,“Barren thin fertile type”(hereinafter referred to as the three kinds of the middle-and-low-yielding fields)of three kinds of middle-and-low-yielding fields;Using network analysis and transport model,to match the topsoil stripping and three kinds of the middle-and-low-yielding fields,formed a plan that strippable topsoil used in three kinds of middle-and-low-yielding fields.On this basis,combining with pilot projects of has been implemented in Wangcheng District,to measure the quality potential,cost and benefits about topsoil stripping and reusing on three kinds of the middle-and-low-yielding fields.The main research conclusions as follows:1.Three kinds of the middle-and-low-yielding fields have the large quality potential,but the potential space is different.Three kinds of middle-and-low-yielding fields by reusing topsoil stripping,the average quality increased from 5.43 to 2.62,increased 2.81average;“Irrigation improved type”,“Waterlogging drainage type”,“Barren thin fertile type” of three kinds of the middle-and-low-yielding fields by reusing topsoil stripping,the average quality increased from5.47,5.20,5.48,to 2.65,2.37,2.76,increased by 2.82,2.83,2.72 average.2.Cost of per unit area of three kinds of middle-and-low-yielding fields is not the same.Three kinds of middle-and-low-yielding fields by reusing topsoil stripping,with a total investment of 974.0888 million yuan,207000yuan/ha,73800 yuan/ha.grade.Among them,“Irrigation improved type”with a total investment of 475.9386 million yuan,139800 yuan/ha,49700yuan/ha.grade;“Waterlogging drainage type” with a total investment of232.0531 million yuan,322500 yuan/ha,113800 yuan/ ha.grade;“Barren thin fertile type” with a total investment of 266.0971 million yuan,457100 yuan/ha,167900 yuan/ha.grade.3.Three kinds of the middle-and-low-yielding fields have different food production potential.Three kinds of middle-and-low-yielding fields by reusing topsoil stripping,can add 8.3916 million kg of grain,increase output value of22.8252 million yuan.Among them,“Irrigation improved type”,“Waterlogging drainage type”,“Barren thin fertile type” three kinds of the middle-and-low-yielding fields respectively add 6.1258 million kg of grain,1.349 million kg of grain,916800 kg of grain,increase output value of 16.6621 million yuan,3.6694 million yuan,2.4937 million yuan respectively.4.Three kinds of the middle-and-low-yielding fields qualitative transformation economically feasible.The cost of upgrading middle-and-low-yielding fields by reusing topsoil stripping is 73800 yuan/ha.grade,lower than the price of “drought to change water” 937500-1125000 yuan/ha.grade in “supplementary farmland trading platform” of Hunan Province presently.So,the project is viable economically.