云雾山不同坡向草地土壤养分的坡面分布特征

结合野外调查和室内分析的方法对云雾山不同坡向草地土壤养分的坡面分布特征进行了研究.结果表明,封育草坡表层(0-15 cm)土壤碳、氮、磷全量远远高于撂荒坡;阳坡表层土壤有机碳和全氮含量随距坡顶距离的延长呈先降后增趋势,而阴坡则随距坡顶距离的增加呈先增后降趋势;全磷在不同坡地的变异性较大.在土壤剖面分布上,3个坡地土壤有机碳、全氮、矿质氮、速效磷和阳离子交换量的含量或值基本随土层的加深而降低,且在大致表现出封育阴坡>封育阳坡>撂荒坡的趋势;pH值则与之相反;速效钾和全磷均呈现出撂荒坡>封育阴坡>封育阳坡.这些结果表明研究区草坡地自然封育后土壤养分状况有所改善,其改善程度以阴坡较大.

Spatial Distribution of Soil Nutrients in Long- term Re-vegetated Slopes in Yunwu Mountains

In this paper, we studied the spatial distribution of soil nutrient components in dif ferent grass sloping lands in the Yunwu Mountains. Results showed that in the horizontal direction, southern slopes and bare lands had a similar distribution of soil organic C and total soil N in surface soils( 0-15 cm), whereas nor thern slopes had an opposite distribution pattern. Additionally, total P varied greatly along sloping lands regardless of slope direction. In soil profiles, soil organic C, to tal N, mineral N, Olsen P, and CEC were all decreased with soil depth and followed the order of nor thern slope > southern slope > bare land, yet pH values presented contrary distribution pattern. The distribution of available K varied with slope type, while total P changed slightly with soil depth. Both soil proper ties followed the order of bare land > norther n slope > southern slope. Our results suggest that soil nutrient conditions can be improved by natural re-vegetation and the improvement of soil nutrients are more obvious in northern slope than southern slope.