The Evaluation Of Cultivated Land Fertility In Sanya

Cultivated land is the essence of the soils, which are the most important resource of agricultural. The quantity and quality of the cultivated land resources have enormous influence on the agricultural production, human material living standards, development of the whole national economy, or even directly related to whole social economical development sustainable development. And the Second National Soil Survey has been more than twenty years, during which our country's cultivated land quality and soil fertility has a great change. So it is necessary to carry out a new investigation and evaluation of the cultivated land, which Create the conditions for rational utilization of cultivated land resources, prevention of soil degradation, co-ordination of agricultural structure, and realizing sustainable development of population, resources, environment.This thesis take the Sanya City, Hainan Province as study area, Based on extensive collection and analysis of data and information of areas, Adopted Arcgis, Access, Excel etc software to establish the basic database of cultivated land resources of Sanya, And Utilizing the AHP and Delphi Method to establish the evaluation index system of cultivated land fertility. Then evaluate soil fertility of cultivated land of Sanya. In this study, the main results are as follows:1 The basic database of cultivated land resources of Sanya and the evaluation index system of cultivated land fertility is established; then fertility of cultivated land evaluation is Completed with the vector data structure; explores a set of effective methods and experience in evaluation of soil fertility of cultivated land in Hainan geographical2 Soil nutrient characteristics of the spatial variability of Sanya city is Analyzed. results showed that:The average concentrations of Total N, Available N, Available P, Available K and Organic matter were 1.04 g/kg,79.85mg/kg,42.99 mg/kg,74.98mg/kg and 19.10 g/kg, pH value of an average of 5.28. The features of the spatial distribution of concentrations of the nutrients were massive distribution. The variation of available P and available K are the largest; Soil nutrients are divided into six standards According to the second soil survey of Hainan Province, Available N, Available P, Available K and Organic matter were mainly fourth grade, first grade, fourth grade, fourth grade, the soil nutrients of Sanya is low. The spatial distribution of concentrations of the pH was massive distribution, mainly in acid and weak acid level. And The area of weak acid level is the largest. 3 According to the comprehensive index of soil fertility evaluation, the cultivated land of Sanya is divided into six classes, evaluation results show that:The total area of cultivated land of Sanya were 166.7 hm2, it accounts for the total land area of Sanya 8.66%. the third and fourth class had a wider distribution in Sanya, fourth class area is largest, it accounts for the total area of cultivated land 40.05%; the second is third class, it accounts for the total area of cultivated land 33.52%; First and second class accounts for less percentage, they respectively account for 4.63% and 9.83%; Fifth and sixth class respectively account for 6.92% and 8.46%。4 Comprehensively analyzing the barrier factors of affecting the class of cultivated land to identify the existing problems of cultivated land use; And the improvement measures and suggestions was put forward.