关键词: 保护性耕作, 主成分分析, 最小数据库集, 隶属度函数, 土壤质量指数, 测墒补灌, 土壤贮水消耗量, 光合速率, 籽粒产量, 水分利用效率, 冬小麦

Abstract: A 9-year field experiment was conducted on the Guanzhong Plain of Shaanxi Province to study the effects of subsoiling, rotary tillage, straw return, no-till seeding, and traditional tillage on the soil physical and chemical properties and the grain yield in a winter wheat-summer maize rotation system, and a comprehensive evaluation was made on the soil quality under these tillage patterns by the method of principal components analysis (PCA).Comparing with traditional tillage, all the conservation tillage patterns improved soil fertility quality and soil physical properties. Under conservative tillage, the activities of soil urease and alkaline phosphatase increased significantly, soil quality index increased by 19.8%-44.0%, and the grain yield of winter wheat and summer maize (expect that under no till seeding with straw covering) increased by 13%-28% and 3%-12%, respectively. Subsoiling every other year, straw- chopping combined with rotary tillage, and straw-mulching combined with subsoiling not only increased crop yield, but also improved soil quality. Based on the economic and ecological benefits, the practices of subsoiling and straw return should be promoted.

Key words: conservation tillage, principal components analysis (PCA), minimum data set (MDS), membership function, soil quality index(SQI), supplemental irrigation by measuring soil moisture content, soil water consumption, photosynthesis, grain yield, water use efficiency, winter wheat.