作 者 ：桂东伟,雷加强*,曾凡江,穆桂金,杨发相
期 刊 ：生态学报 2010年 30卷 7期 页码：1780~1788
Keywords:soil quality, farmland, utilization intensity, oasis, Cele,
摘 要 ：土壤质量研究对于区域土地可持续利用及当地环境维护具有重要价值。以处于极端干旱背景下的塔里木盆地南缘策勒绿洲为研究区，以农田这一重要的土地利用类型为研究对象，探讨在绿洲化进程中不同农田利用强度对绿洲荒漠土壤的影响。2004年根据当地农民耕作习惯建立4块试验农田，分别代表当地典型的农田利用强度。通过土壤粒径分布分形特征，及基于土壤养分指标的土壤质量指数(SQI)、基于生产力数据的产量可持续性指数(SYI)分析，多角度探讨农田在不同利用强度下的土壤质量分异特征。研究表明农田位置与人为管理强度会对土壤质量产生重要影响，在绿洲边缘对农田开发利用应当采取谨慎的态度及合理的管理方式。研究在客观分析并揭示绿洲化进程中农田土壤质量分异的同时，也为绿洲农田可持续利用管理提供科学建议。
Abstract:Soil quality is a key environmental factor in developing sustainable agricultural. Soil quality research in extremely arid regions, aiming at determining effects of different utilization, is much more limited. The Cele oasis located the southern margin of Tarim Basin of Xinjiang, China was selected as a study area. Agriculture is the main land use type. However, the management intensities differ in the oasis and in the process of oasis growth. In 2004, four experimental fields were established, representing four typical land use types according to local farmers tillage practices, namely newly cultivated land (NEF), a field with normal manure (NMF), a field with high manure (HMF) and a field in the oasis′ interior (OIF), in order to analyze the effects of land use types on soil particle\|size distributions (PSDs) and soil nutrient contents. Additionally, the soil from an uncultivated control plot (CTP) was analyzed for comparison. The soil quality index (SQI), calculated by applying principle component analysis (PCA), were used to evaluate the effects of different land use types. The sustainable yield index (SYI) was calculated to evaluate the sustainable productivity of these land use types, based on the data from 4 years studies. Our results indicate (i) statistically significant differences in PSDs, SOM, total nitrogen N (TN), total phosphorus (TP) and available phosphorus (AP) between the different farmlands; (ii) NEF, situated in the desert oasis ecotone, showed the lowest soil quality, even lower than CTP, and the lowest indicator values; (iii) fertilization of NMF and HMF which are also situated in the desert oasis ecotone resulted in a positive effect on PSDs and soil nutrient contents. This result is different from those from other regions due to the fact that the original natural soil (CTP) under the given extremely arid conditions has low background values. However, the sustainable productivity of these farmlands is low, and much underground water is being consumed; (iv) the farmland (OIF) situated in the oasis interior showed the highest level among all assessments. Our study indicated that farmland in the desert oasis ecotone should be reclaimed prudentially, that a sustainable development insight must be used, and that rational management practices and advanced technologies are needed. These study results could be beneficial for refining agricultural management practices and for improving sustainable land use in the oasis and in the process of oasis growth.
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