荒漠绿洲的土壤异质性分析——以银川平原为例

以银川平原为例,分析了荒漠绿洲主要土壤类型即淡灰钙土、灌淤土、风沙土、潮土的地带性分布、机械组成及分维数、肥力特征等异质性表现。各土壤类型的平均分形维数大小顺序是:灌淤土>潮土>淡灰钙土>风沙土;分维数的大小确切地反映了银川平原主要土壤的组成和质地。0-80cm范围内各土壤类型的垂直分维特征表现为:淡灰钙土和风沙土随着土壤深度增加,分维值也随之变大;潮土分维值的垂直分异则表现为0-40cm的分维值较高,土壤深度>40cm后分维值随之下降;灌淤土质地均匀一致,分维值变化很小。灌淤土和潮土的全N含量明显高于淡灰钙土和风沙土,除风沙土外,其它3种土壤类型的全P含量相差不大,荒漠土壤的全K含量都比较高。除风沙土,灌淤土、潮土、淡灰钙土的土壤有机质含量从表层向下基本上呈下降趋势,而且灌淤土和潮土的土层厚。主要土壤类型的形成和发育之间存在着一定的联系。最后针对土壤的异质性特点,提出土地利用的分区建议。

Analysis on Soil Heterogeneity of Oasos in Desert Region——A Case Study on Yinchuan Plain

Soil heterogeneity of oasis in desert region in Yinchuan plain were studied.The soil heterogeneity includes zonal distribution features,mechanical composition,fractal feature,fertility level etc.The mean fractal dimension displayed the following order:irrigation-silting soil > fluro-aquic soil > ochr-sierozem soil > sandy soil.The values also reflected the composition and texture of main soil types of oasis in Yinchuan plain.From the top soil layer down,different vertical fractal dimention change occured among four soil types and the content of organic matter of soils was decreased absolutely but sandy soil.Soil vertical layeres of irrigation-silting and fluro-aquic soil were deeper,and total N content is higher than the two other soil types.There was no clear differences in total P content among those soils but sandy soil,which total K content of soils of oasis was higher level in desert region.Based on soil heterogeneity,some advices were given on how to use land of oasis appropriately in desert region.