摘要
以东北黑土区典型漫岗坡耕地为研究对象,测定次降雨条件下整个集水盆地出口处的径流体积及其含沙量,研究侵蚀泥沙的粒径分布特征、碳氮富集度以及可溶性养分的流失状况。结果表明,研究区只有在强降雨的情况下才会在集水盆地尺度上发生水土流失现象。20.5 mm降雨条件下(2006年8月1日)径流泥沙含量为1.0～2.5 g/L,泥沙C、N富集系数分别为2.10和3.31。径流液中DOC的浓度介于2.47～3.93 mg/L之间,TN浓度介于1.61～3.28 mg/L之间,径流携带养分量在整个养分流失过程中是不可忽视的流失途径。侵蚀泥沙(未加分散剂)的团聚体组成和原土壤有很大差异,径流泥沙的流失主要是粒径为0.053 mm以下的团聚体,尤其是0.002～0.02 mm的粉粒团聚体为主。
A typical undulating farmland in black soil region of Northeast China was taken as a case study to analyze the properties of soil loss caused by erosional precipitation events based on measurement of sediment and its nutrients and particle size in different geomorphic positions and the outlet of the watershed. The results showed that soil loss only happened in high rainfall intensities. This study takes the runoff event on August 1st, 2006 for example. The sediment concentration in runoff is in range of 1.0-2.5 g/L. Nutrient enrichment occurred in sediment and the enrichment ratio of carbon and nitrogen is 2.10 and 3.31, respectively. The soluble carbon and nitrogen in runoff is 2.47-3.93 mg/L and 1.61-3.28 mg/L. The loss of soluble nutrients is also an important way of nutrient loss under water erosion. The aggregate size distribution of the eroded sediment was drastically different from that of the original soil. Aggregates smaller than 0. 053 mm, especially the size between 0. 002 mm and 0.02 mm, is the main form of the sediment.
出处
《干旱地区农业研究》
CSCD
北大核心
2008年第6期224-229,共6页
Agricultural Research in the Arid Areas
基金
国家自然科学基金资助项目(40471125)
国家自然科学基金(40801071)
吉林省科技发展计划资助项目(20050206-4)
国家科技支撑项目(2006BAD15B01)
东北地理与农业生态研究所学科前沿领域项目(KZCX3-SW-NA3-31)
关键词
黑土
土壤侵蚀
含沙量
团聚体
富集系数
black soil
soil erosion
sediment
aggregate
enrichment ratio
