西藏阿里典型耕地土壤的主要特征及其质量评价

The Primary Characteristic and Quality Evaluation of Typical Farming Soil in Ngari Region, Tibet

通过对西藏阿里地区耕地土壤的实地踏勘和采样分析，选取有机质、有效氮、有效磷、有效钾、土层厚度、pH值、物理粘粒含量、障碍层深度、地下水位、坡度等共10项土壤质量评价指标，应用基于评价指标隶属度的模糊集加权的土壤质量综合评价方法。结果表明了耕地土壤具有质地的沙质性，团聚体的低质性，富有机质的低矿化特性，以及碱性环境下的养分较丰富性等特征。灌淤土的质量较好，其次是耕作草甸土和耕作亚高山草原土，最次的是潮土。

The environment and ecosystem in the Qinghai-Tibet Plateau are very fragile. A lot of environment and ecological issues, such as soil erosion, land desertification etc, is becoming increasing serious under influence of human activity in Ngariregion of western Qinghai-Tibet Plateau. For the implement of soil and ecological environment improvement program in this region, it is necessary to investigate the primary characteristic and evaluate quality offarming soil. In this study, field investigation and soil sampling were carried out, and 10 indicators： soil organic matter, available nitrogen, available phosphorus, available potassium, pH, physical clay, depth of soil layer, depth of obstacle horizon, depth of underground water, and slope, were selected to evaluate the soil quality by method of weighed membership values of the selected indicators. Results Showed the farming soils have four special characteristics： arenaceous texture;poor aggregation; rich soil organic material with low mineralization, rich soil nutrient with high Ph, and the order of soil quality of different soil type isirrigafing warped soil 〉 cultivated prairie soil 〉 sub-alp steppe soil 〉 calcareous soil.