Wei Xiao-Rong, Shao Ming-An
Institute of Soil and Water Conservation, Northwest A & F University, Yangling 712100, Shaanxi, China.
Ying Yong Sheng Tai Xue Bao. 2009 Nov;20(11):2710-5.
Soil chemical properties play important roles in soil ecological functioning. In this study, 207 surface soil (0-20 cm) samples were collected from different representative landscape units in a gully watershed of the Loess Plateau to examine the distribution characteristics of soil pH, cation exchange capacity (CEC) and organic matter, and their relations to land use type, landform, and soil type. The soil pH, CEC and organic matter content ranged from 7.7 to 8.6, 11.9 to 28.7 cmol x kg(-1), and 3.0 to 27.9 g x kg(-1), and followed normal distribution, log-normal distribution, and negative binomial distribution, respectively. These three properties were significantly affected by land use type, landform, and soil type. Soil CEC and organic matter content were higher in forestland, grassland and farmland than in orchard land, and soil pH was lower in forestland than in other three land use types. Soil pH, CEC and organic matter content were higher in plateau land and sloping land than in gully bottom and terrace land. Soil CEC and organic matter content were higher in dark loessial soil and rebified soil, while soil pH was higher in yellow loessial soil. Across all the three landscape factors, soil CEC and organic matter content showed the similar distribution pattern, but an opposite distribution pattern was observed for soil pH.
土壤化学性质在土壤生态功能中发挥着重要作用。本研究从黄土高原沟壑流域不同代表性景观单元采集了207个表层土壤（0 - 20厘米）样本，以研究土壤pH值、阳离子交换量（CEC）和有机质的分布特征，及其与土地利用类型、地形和土壤类型的关系。土壤pH值、CEC和有机质含量范围分别为7.7至8.6、11.9至28.7厘摩尔每千克（-1）和3.0至27.9克每千克（-1），分别遵循正态分布、对数正态分布和负二项分布。这三种性质受土地利用类型、地形和土壤类型的显著影响。林地、草地和农田的土壤CEC和有机质含量高于果园，林地的土壤pH值低于其他三种土地利用类型。塬地和坡地的土壤pH值、CEC和有机质含量高于沟底和梯田。黑垆土和红胶土的土壤CEC和有机质含量较高，而黄绵土的土壤pH值较高。在所有三个景观因素中，土壤CEC和有机质含量呈现相似的分布模式，但土壤pH值呈现相反的分布模式。
