|其他摘要||Soil microbes play an important role in maintaining ecosystem stability and function, community structure and diversity of its features is an important indicator of soil quality evaluation. In arid areas, desert when reclaimed farmland, significantly changed the way the land use and cover, correspondingly cause a series of changes in vegetation, litter, and other soil nutrients and moisture, these changes would inevitably lead to soil microbial community structure and diversity sex change, thereby affecting the function of the soil, and even soil quality and environmental effects. Use patterns or changes in land management measures, will significantly affect the soil nutrient status and soil microbial community structure and diversity. However, the current research in arid zones Microbial revolves around gray desert soil bacterial communities expand, can not cover the complexity of Xinjiang soil type and cropping history, its findings need further verification. Also, in response to desert reclamation of soil microbial community how the presence of what effect is unclear. Soil microbial biomass、community structure and microbial diversity were analyzed by using phospholipid fatty acid（PLFA）methods, based on the soil of oasis field typical basins (Manas River Basin, Jimsar river, Sangong river、Sigong river, shuimo River) and the adjoining desert in the southern Gurbantunggut Desert.
Major findings:(1)The total PLFAs 、Fungi PLFA、Bacteria PLFA、Gram-positive bacteria PLFA(G+) and Gram-negative bacteria PLFA(G—) had generally increased after reclamation of desert; (2)Microbial community structure has undergone significant changes: In the early desert reclamation (3a), fungal PLFA / bacterial PLFA ratio decreased 48%, G+ PLFA / G— PLFA ratio (Gram-positive bacteria and Gram-negative bacteria PLFA ratio) reduce 67%. (3)But with the extension of cultivation years, these two ratios did not change significantly, suggesting that compared with reclamation, desert reclamation behavior have a more intense effect on the soil microbial community. In addition, the soil microbial community diversity overall upward trend with years of use. (4)The diversity index showed a slight decrease after reclamation of 50 years but still higher than the desert soil. The total soil microbial PLFA and most bacteria PLFA content had significant negative correlation with soil conductivity and had significantly positive correlation with total nitrogen and organic carbon. Desert in the reclamation process due to irrigation increased soil moisture and reduces soil salinity, while total nitrogen and organic carbon content increased, these changes are the main reason for change of soil microbial communities. This study suggests that desert reclamation help improve soil microorganisms, help to improve soil quality.|