Comprehensive assessment methodology of soil quality under different land use conditions

As traditional method of soil quality assessment cannot meet the need of modern agricultural development, the paper brings forward a comprehensive evaluation method of soil quality：Soil quality index (SQI), in order to provide theoretical support and reference for agricultural production, field selection of farmland and the protection of agriculture environmental. This method had been applied to the soil of seven patterns of land-use (grain fields, woodlands, wetlands, wasteland, orchard, vegetable garden, lawn) in Beijing suburbs, and was compared with the conventional methods. The results showed that the soil fertility assessed by Fuzzy membership function model was ranked as follows: wetland＞vegetable garden＞grain crop fields＞forest land＞orchard＞wasteland＞grassland. The soil environment quality was assessed by single factor pollution index and Nemerow indices of heavy metal, the contamination index in the order: wetland＞vegetable garden＞wasteland＞orchard＞forest land＞grain crop fields＞grassland. The comprehensive quality of soil which was evaluated by SQI, ranked as follows: wetland＞grain crop fields＞vegetable garden＞orchard＞forest land＞wasteland＞grassland. In addition, some significant topics were discussed such as model scope, division of evaluation results, etc. It was concluded that SQI model not only can be applied to different land-use types, but also reflects the spatial variability of soil properties and soil critical information, e.g. fertility and pollution. It can achieve qualitative and quantitative analysis of soil comprehensive quality, and meet the needs of agricultural production.