陕北黄土坡面微地形土壤化学性质

Soil chemical properties of micro-topography on loess slope in Northern Shaanxi Province

由于侵蚀等原因使陕北黄土坡面不平整形成了各种微地形,造成了土壤化学性质的差异。通过对黄土区自然恢复状态下的微地形土壤化学性质进行调查,分析不同微地形之间的土壤异质性。结果表明:1)研究区内5种微地形与原状坡相比相对土壤化学性质均有一定改善,土壤有机质质量分数表现为塌陷微地形最高,切沟、缓台和浅沟微地形居中,原状坡和陡坎微地形最低;2)全效养分中,全效氮的质量分数与有机质质量分数规律一致,而全效磷和全效钾的质量分数差异较小;3)速效养分中,缓台、切沟、塌陷微地形中3种速效养分的质量分数较高,而陡坎微地形速效养分质量分数比较低;4)土壤阳离子交换量随土层深入而减小,在5种微地形中顺序为浅沟>塌陷>切沟>原状坡>缓台>陡坎,pH值和碳酸钙质量分数在5种微地形中差异较小;5)通过对5种微地形和原状坡的3个土层的土壤化学性质进行灰色关联分析,发现塌陷和缓台微地形的关联度最高,而原状坡和陡坎微地形最低。

Due to erosion and other reasons,loess slope in Northern Shaanxi occurred unevenness,which formed a variety of micro-topography and led to differences in soil chemical properties.The soil chemical properties of the micro-topographies were investigated and analyzed in this paper.Results showed that： 1） compared with undisturbed slope,soil chemical properties of five types of micro-topography in study area were improved to some extent.Contents of soil organic matters in the 0-20 cm soil layer for the five micro-topography types were given as follows： collapse gully,platform and ephemeral gully（EG）undisturbed slope and scarp.2） For the five types of micro-topography,the distribution of total N agreed with the soil organic matters,and there was no big difference between total P and total K.3） Except for scarp,available nutrients in collapse,gully,ephemeral gully（EG） and platform were higher than those in undisturbed slope.4） Cationic exchange capacity decreased with soil depth and performed the order of ephemeral gully（EG） collapse gully undisturbed slope platform scarp.There were no significant difference between CaCO3 and pH.5） From the analysis of grey correlation on the soil chemical properties of three soil layers of the five types of micro-topography and undisturbed slope,it can be concluded that the collapse and platform gained the closest correlation,but undisturbed slope and scarp were the worst.