陕北黄土坡面微地形土壤物理性质研究

Soil Physical Properties of Micro-topography on Loess Slope in North Shaanxi Province

陕北黄土坡面由于侵蚀等原因使坡面不平整,形成了各种微地形,造成了土壤物理性质的差异。对黄土高原丘陵沟壑区的微地形土壤物理性质进行了调查分析。结果表明,研究区内5种微地形与原状坡相比较,塌陷、切沟、浅沟、缓台的土壤物理性状均有所提高,而陡坎的各项性能比原状坡有所降低,主要表现在0—20cm土壤。土壤容重在0—20cm由大到小的顺序为:原状坡>陡坎>缓台>浅沟>切沟>塌陷。土壤含水量、最大持水量、田间持水量和毛管持水量表现出比较一致的变化趋势,塌陷、缓台、切沟和浅沟这4种微地形孔隙和水分状况均高于原状坡和陡坎。土壤的总孔隙度、毛管孔隙度和非毛管孔隙度的变化趋势和土壤持水性能的变化趋势一致。通过对5种微地形物理性质进行灰色关联度分析发现,其灰色关联度由大到小的顺序为:塌陷>切沟>浅沟>缓台>陡坎>原状坡。

Due to erosion and other reasons,loess slope is uneven and a variety of micro-topographies formed,which result in differences in soil physical properties in different spatial positions in Northern Shaanxi Province.This paper investigated and analyzed the soil physical properties of the micro-topographies in loess hilly-gully region.The comparison of five types of micro-topography with undisturbed slope showed that the soil physical properties of collapse,gully,ephemeral gully and platform increased to a certain degree,but decreased in scarp.This usually occurred in 0—20 cm soil layer.Soil bulk density of the 0—20 cm soil layer changed in the following order： undisturbed slopeplatformscarpephemeral gullygullycollapse.Soil water content,maximum moisture capacity,field capacity and capillary moisture capacity showed relatively similar trend,higher values being recorded in collapse,platform,gully and ephemeral gully than undisturbed slope and scarp.The change of soil total porosity,capillary porosity and non-capillary porosity coincide with soil water retention.The analysis of grey correlation between the five types of micro-topography and the soil physical properties indicated that grey correlation followed an order of collapse,gully,ephemeral gully,platform,scarp,undisturbed slope.