粤西典型崩岗侵蚀剖面可蚀性因子初步分析  

The preliminary investigation of soil erosive factors in granitic weathering rinds in western Guangdong province

作　　者：王艳忠[1,2,3] 胡耀国[4] 李定强[4] 杨少芹[4] 

机构地区：[1]中国科学院华南植物园 [2]中国科学院研究生院北京100049 [3]广东省生态环境与土壤研究所广东广州510650 [4]广东省生态环境与土壤研究所

出　　处：《生态环境》2008年第1期403-410,共8页Ecology and Environmnet

基　　金：广东省自然科学基金项目(05103595);广东省科技计划专项(2006A36801001);广东省自然科学基金项目(04101225)

摘　　要：广东崩岗侵蚀区土壤可蚀性研究是认识崩岗侵蚀机制的重要环节，而不同粒级土壤颗粒组成、有机质含量与可蚀性因子K又是评价土壤可蚀性的重要参数。针对粤西典型红壤侵蚀区的两种不同侵蚀强度的花岗岩风化壳侵蚀土壤剖面，从垂向上研究了两种剖面中土壤颗粒组成特性、有机质空间变化，并利用USLE型中的土壤可蚀性K因子修正方程计算了两种不同侵蚀程度剖面的可蚀性K因子，分析了三个指标与土壤侵蚀的关系，发现典型花岗岩区土壤侵蚀剖面的土壤颗粒组成、有机质和可蚀性K因子呈现较好的规律性，表现为：自剖面上部至下部，土壤颗粒组成逐渐变粗，土壤有机质质量分数递减，可蚀性K因子逐渐升高，三个指标在红土层与砂土层过渡区（剖面2～3m深度范围）分界明显，界面上下含量相差悬殊；相同层位对比研究发现，强侵蚀剖面相对于弱侵蚀剖面，土壤的黏粒与土壤有机质质量分数更低，可蚀性K因子值更大；两剖面中三个指标的相关性研究表明，土壤黏粒、粉粒、有机质质量分数与土壤可蚀性K因子具有显著相关性。综合分析认为，在广东崩岗侵蚀区，不同粒级土壤颗粒组成、有机质含量及可蚀性K因子的空间变化均可有效地反映来源于花岗岩风化壳的土壤之可蚀性。Soil erodibility is an essential content of studying forming mechanism of＂ benggang ＂erosion, while particle of soil with varied size, content of soil organic matter and K factor of USLE model are typical assessing indices of soil erodibility. The purpose of this present paper is to inspect spatial variation and the co-relationships of these three indices in two soil profile with different erodibility in granitic weathering rinds spreading in western Guangdong province. According to the results of our investigation, we have obtained the following cognitions, which are, Firstly, varieties of these three indices have displayed obvious evolution regulation spatially, i.e. from the top to the downside of these two profiles, the size of total soil particle became smaller and smaller; the content of soil organic matters decrease with depth; compared with the indices of particle size and soil organic matters content, K factor show a converse varied tendency, i.e., the value of K factor increases with the depth of the two soil profiles. Secondly, notable differences of the three indices occurred at the two sides of the transitional zone between the red soil horizon and sand soil horizon in the two studied profiles, which are,（1） contents of clay particles and organic matters are higher in the profile with weak soil erodibility than that in profile with intensive soil erodibility, and （2） K factor has the converse distributing tendency compared with the former two indices in the two soil profiles. Finally, in the two soil profiles, the content of soil particle with size ranging from 0.1-0.002 mm and that with size lower 0.002mm, as well as the content of soil organic matters, have good correlation with each other. In summary, in＂benggang＂ erosive area, content of soil organic matter, content of silt particle and clay particle, as well as K factor, can effectively be applied in tracing erodibility of soil developed from granitic weathering rinds.

关 键 词：花岗岩侵蚀土壤剖面 颗粒组成 有机质 K因子 土壤可蚀性 

分 类 号：S157[农业科学—土壤学]