Abstract: To assess the soil quality under different land use practices in the high-cold region and identify the key influencing factors on soil quality under different land use types,174 soil samples from four main land use practices,including forests,shrubs,grasslands,and cultivated lands,were collected on the southern slope of the Qilian Mountains. A minimum data set (MDS) was established using principal component analysis to comprehensively evaluate soil quality under different land use practices in the study area. The results showed that the soil quality indices for forests,shrubs,grasslands,and cultivated lands were 0.535,0.519,0.466,and 0.544,respectively,with the order of cultivated lands>forests>shrubs>grasslands. Corresponding to the soil quality classification,the soil quality levels for grasslands were classified as Grade III,indicating a “medium” level,while the soil quality level for cultivated lands,forests,and shrubs was classified as Grade IV,indicating a “above-average” level. There were interactions among the key indicators of soil quality. Scientific classification management should be implemented for land in the research area. Regarding to the microorganisms affecting soil quality,the rational development and application of environmentally friendly,green and efficient new biotechnologies are effective measures to address the microbial indicators influencing soil quality in the study area.

Key words: Soil quality, Minimum data set, South slope of Qilian Mountains

摘要： 为了评估高寒地区不同土地利用方式下的土壤质量状况，明确不同土地利用方式下的土壤质量的关键影响因子，在祁连山南坡采集了林地、灌丛、草地及耕地4种主要土地利用类型的土壤样品174份，通过主成分分析(Principal component analysis,PCA)建立最小数据集(Minimum data set，MDS)，综合评估研究区不同土地利用方式下的土壤质量。结果表明：林地、灌丛、草地和耕地土壤质量指数值分别为0.535，0.519，0.466和0.544，表现为耕地＞林地＞灌丛＞草地，对土壤质量分级为Ⅰ~Ⅵ级，对应指数分别为≤0.3，(0.3~0.4］，(0.4~0.5］，(0.5~0.6］，(0.6，0.7］和>0.7,草地等级为Ⅲ级，处于“中等”水平；耕地、林地和灌丛土壤质量等级为Ⅳ级，处于“中等偏上”水平。土壤质量关键指标间存在互相影响，因此，建议研究区域土地要实施分类科学管理。此外，合理开发和应用绿色高效的新型生物技术是应对影响研究区土壤质量的微生物指标的有效措施。

关键词: 最小数据集, 土壤质量, 祁连山南坡