民勤绿洲耕地荒地退耕还林地土壤肥力及物理特性比较研究

摘要

采用野外调查采样、室内实验、统计分析和地统计分析的方法研究了民勤绿洲东湖灌区在不同的土地利用类型下的土壤肥力及物理特性。结果显示出土地利用方式不同对土壤水分、养分、盐分有明显的影响,但是对pH值的影响不是很大。土壤水分变异系数最大的是退耕还林地达到了50％左右,最小的是农田,退耕还林地中出现了土壤水分较少的现象。电导率的最大值出现在荒地中为4560.7 μS/cm,其次是退耕还林地;N、P、K在不同的土地利用类型中表现出不同的特征,但呈现出富K、贫P、富N的总体特征;pH值呈现出碱性特征,变异系数最大值也是出现在退耕还林地中。研究结果能为民勤绿洲东湖灌区合理调整土地利用方式及进行地表植被恢复提供参考依据。%Soil fertility and physical properties under different land use types in Minqin oasis of East Lake irrigation area were studied by field survey, lab experiment, statistical analysis and geostatistics analysis methods. The results showed that land use types influenced obviously on soil moisture, nutrients and salinity, but influenced little on soil pH. The highest variation coefficient of soil moisture, about 50%, occurred in the returning farmland to forest, while the smallest one occurred in the farmland. Soil moisture deficient phenomenon appeared in the returning farmland to forest The maximal conductivity, 4 560.7 μS/cm, occurred in the wasteland, followed by the returning farmland to forest. N, P and K displayed different characteristics under different land use types, but showed a general feature of rich in N and K, but poor in P. All soils were alkaline, the maximal variation coefficient of soil pH occurred in the returning farmland to forest Those above conclusions can provide the reference for the reasonable adjustment of land use and the restoration of surface vegetation in Minchin oasis of East Lake irrigation area.