| Geochemical evaluation of soil quality is based on useful element, toxic and harmful elements, concentration levels of organic pollutants of soil to carry out level assessment of land quality about the basic functions of the land. Geochemical evaluation of land quality is based on the results of multi-objective regional geochemical survey (also known as the Geological Survey of agriculture) and theory of eco-geochemical to make rational use of land resources for the purpose of carrying out basic geological work.Supporting by Golden Land Project of Sichuan Province, this paper cites land consolidation area of Tianfu town of Suining City as an example to collect samples about profile of soil, rocks, surface soil, root and crop seeds, and test the entire volume of elements, contents of effective state, total quality of rock samples. We used geochemical cycle theory and took multi-object regional geochemical survey methods and evaluation of earth system technology roadmap to research distribution and dispersed concentration of elements in soil. We also understudied the related geochemical indicators and distribution, and researched geochemical characteristics of the area in soil and rock. In order to improve land using, set out program of agricultural production with soil fertilization, select pollution-free agricultural products and agricultural production base, adjust structure of planting, improve quality of life of residents, ensure the safety of agricultural products, we analyzed the law of migration, transformation, accumulation of geochemical elements in soil - rocks, soil - crop seed. This study will provide a model to study the effective application of the results of geological survey in the aspects of Collation of arable land, the development of agricultural production, quality of life of residents. Evaluating soil quality of this area, we conclude:1. Analyzed the content and spatial distribution characteristics of the total content of 21 elements, organic matter and value of pH, we know: in constant and trace elements, P, K2O, CaO, MgO are controlled by geological background, which had a high level in the eastern, northern and Pingba areas of study area; Content of Se is higher in overlying soil of Q4; Heavy metal elements contents in Pingba alluvial area are relatively high, which have more related with human activities.2. The results of comparing different soil types are show that, heavy metals are enriched in Q2 and Q3, N, P, S with a high level in Q4; Alluvial and residual materials enriched heavy metals than Slope sediments and the residual slope sediments; Oxide content in purple Soil is higher than paddy soil and yellow soil, paddy soil with a high level of Hg.3.The laws of element migration and transformation show that: in the rock - soil system, heavy metals and a large amount of nutrients performance for the enrichment, trace elements in wet performance; Vertical profiles in the heavy metal elements, As and Pb are expressed as enrichment in humus layer, leaching capacity layer and deposition - parent material layer. Cd, Cu, Hg, Zn performance for the role of leaching and relocation at all levels in the vertical profile; In constant and trace elements, N , P, S performance for the role of leaching and relocation at all levels in the vertical profile. The trace element of B shows up enrichment in Humus layer and leaching layer, leaching and relocation in deposition layer.4.According to the indicators of the corresponding elements in national standards, the soil fertility and environment was evaluated, the land quality was land geochemical comprehensive assessed. The result shows that in the study area, the land area of good quality is 784.03 hectares, accounting for 52.23%, the land area of middle is 712.31 hectares, accounting for 77.5%, the lower level land accounts for 0.36%.5.Comprehensive evaluation of land quality shows that there was no index-exceeding district in the work area. The most land in western and north-western was classified level 2 or3, the most land in Bai He Lin village, Ma Dao Village, Shi Shan village was classified level 3, which is caused by excessive plant samples, and part land of level 4 was appeared in punctuate distribution. Generally, the land quality is good.
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