Study On The Gradation Of Farmland In Jingyang County

As an important practice field of land evaluation theory, gradation of farmland has been an emphasis measure of conversion from management in quantity to synthetic one in quantity and quality on land. The study of classification and gradation of farmland is important to the government's policies of agriculture development, farmland exploration, field basic construction and farmland sustainable development.With Jingyang County in Shaanxi as an example, study on the base of actual situations of Jingyang County with deeply analyzing correlated foundational data, by the methods of investigation on the spot, the indoor data analysis, according to the regulations of the classification and gradation for agricultural land. Methods, which have been adopted by the gradation of arable land in Jingyang County, are the factor method and the amending method.The rationale of amending method: First, use factors to calculate the natural quality scores of classification units. Then, adamant the scores with the production potential of temperature (climate), the level of land-use and economics, and we can get the natural indexes and economic indexes. At last, make the economic and geographic adamant on these indexes to gain the result and the divisions-level.Thought of factor method: Make the individual evaluation with natural factors and socio-economic factors reference to the LESA system pattern of the USA. Calculate the evaluation values of natural factors and socio-economic factors. And then take unit area standard grain output as farmland quality index to confirm the best natural proportion. Sum two values to gain the final values of gradation units, according to which, farmland is divided into the classes.It proved that natural amending method is more practical on the basis of the comparative analysis of the results calculated. So we take the gradation by natural amending method as the final result and make the analysis of the special distribution and characteristic of land grade. The agricultural land is divided into five gradations, the first gradation is to the highest, and the fifth is to the lowest. The area distribution of each grade is rather even; the land grade which has better natural foundation or dominant position is higher.