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以干旱区三工河流域下游绿洲作为研究区,应用GIS和数理统计学方法,通过对当地农作物轮作制度的调查和历史资料的分析,遴选6种主要作物组合系统,并利用1982,1999和2003年土壤养分数据,分析干旱区绿洲土壤养分对农作物系统变化的响应．结果表明:(1)三工河流域绿洲不同时期的政策、法规和市场变化直接影响了作物系统的变化,研究区土壤有机质经历了先下降后上升的变化过程,碱解氮、速效磷和速效钾含量随土地耕作年限的增加增幅明显;(2)耐盐碱作物和粮食作物向棉花的转变不利于土壤有机质的积累,而粮食作物、棉花等向多年生作物的转变使得土壤有机质含量明显增加;(3)干旱区绿洲土壤总体表现为“碳汇”的过程,说明人类农业活动基本合理,绿洲生态环境正逐步得到改善．
Taking the lower oasis of the Sangong River Basin in the arid area as the research area, GIS and mathematical statistics were used to select six main crop combination systems through the investigation of the rotation system of local crops and the historical data. In 1982,1999 and 2003 Annual Soil Nutrient Data to Analyze Responses of Soil Nutrients to Crop System Changes in Oasis Arid Areas. The results showed that: (1) The policies, regulations and market changes of oases in Sangong River Basin directly affected the changes of crop system. The soil organic matter in the study area experienced the process of first decreasing and then increasing, the contents of available nitrogen, available phosphorus, (2) The change of salt-tolerant crops and grain crops to cotton is not conducive to the accumulation of soil organic matter, while the change of the crop, cotton and other perennial crops makes the content of soil organic matter increase obviously; (3) The oasis soil in the arid area shows the process of “carbon sink”, which shows that the human activities in agriculture are basically reasonable and the ecological environment in the oasis is gradually being improved.