The Evaluation Of Cultivated Land Fertility And Spatial Characteristics Of Each Soil Nutrients Based On GIS In Luyi County

Land is the material basis of the living and development of human life, and it is the most fundamental source of all the material production. Cultivated land is the essence of land. The quantities and qualities of cultivated land resources have great influence on the development of agricultural production, the material level improvement of human society, even the development of the whole national economy, and the key factor influencing the cultivated land quality is cultivated land fertility. With the fast growth of population and the continuous development of social economy, the demand for food increases significantly, and food becomes in shorter supply day by day. However, the base maintaining food production—cultivated land, decreases gradually in the rapid advancing process of industrialization and urbanization, thus exacerbating the hidden trouble and sounding the alarm of China,s food safety. Cultivated land safety ensures food production safety. Both the gradually decreasing total cultivated land area and the increasingly degrading cultivated land quality are endangering China,s cultivated land safety. Luyi County is an important food production base of China. Facing China,s rapid population increase, continuing declined cultivated land area and gradual degradation of cultivated land quality, to ensure national food security and the healthy rapid social economy development, carrying out the evaluation of cultivated land fertility research of east Henan province plain area is of great significance on the construction of China,s land quality and the enhancement of increased and stable production capacities.Luyi county was selected as the study area in this paper. Based on the built GIS software platform, we accomplished the evaluation of cultivated land fertility in this area. This paper is divided into seven parts.Part 1: This part mainly introduces the background as well as the significance of the research, and reviewed the current status of the evaluation research of cultivated land at home and abroad, putting forward the main research content and technical routes of this paper.Part 2: We conclude and summarize the theory and common methods of cultivated land fertility evaluation research.Part 3: A comprehensive introduction to the study area of this research - the profile of Luyi County of Henan Province, including the natural geography and socio-economic status.Part 4: Analysis, processing, interpolation of the collected information and data, including database development, evaluation unit determination, analysis and operation of soil nutrient spatial characteristics. Part 5: We give comprehensive evaluation of cultivated land fertility of the research area and draw the cultivated land fertility evaluation map of Luyi County.Part 6: Analysis of the cultivated land fertility evaluation results.Part 7: Main conclusions and the existing problems. Through the above research, the main conclusions are as follows:(1)The total cultivated land area of Luyi County is 83346.24 hectares, of which the first grade land area is 14962.47 hectares, accounting for 17.95% of the county,s total cultivated area. The second grade land area is 33356.45 hectares, accounting for 40.02% of the county,s total cultivated land area. The third grade land area is 25069.06 hectares, accounting for 30.08% of the county,s total cultivated land area. The fourth grade land area is 9958.26 hectares, accounting for 11.95% of the county,s total cultivated land area. The cultivated land area order of each grade is: the second grade>the third grade>the first grade>the fourth grade. From the distribution area,s point of view, the second grade and the third grade take the main parts, accounting for 70.1% of the county,s total cultivated land area;From the distribution geographical point of view, as the singleness of Luyi county,s topography and physiognomy, the whole county area varies little, each grade cultivated land have no obvious distribution rules. However, generally speaking, the first and the second grade land mainly distribute in the rivers nearby.(2)The spatial distribution of each soil nutrients varies, but there are certain similarities in some areas, soil type and texture type have obvious impact on soil nutrient content. The average content of the main soil nutrient such as organic compound, total nitrogen, effective phosphorous and quick result potassium has the same distribution rules on each grade cultivated land: the first grade>the second grade>the third grade>the fourth grade. The coefficient variation (CV) of organic compound, total nitrogen, effective phosphorous and quick result potassium is 9.58%, 10.65%, 27.98% and 25.31%, respectively, of which organic compound shows low variability, total nitrogen, effective phosphorous and quick result potassium show moderate variability. Overall, Luyi County has relatively abundant quick result potassium and low organic compound content.