紫色土陡坡耕地顺坡垄作条件下的土壤及其流失特征  

Characteristics of Purple Soil and Soil Loss on Down-slope Furrow Tillage Sloping Farmland

作　　者：严冬春[1] 文安邦[1] 龚长文 袁雪峰 

机构地区：[1]中国科学院水利部成都山地灾害与环境研究所,山地表生过程与生态调控重点实验室,四川成都610041 [2]重庆市忠县水务局,重庆忠县404300

出　　处：《山地学报》2014年第3期314-319,共6页Mountain Research

基　　金：国家自然科学基金(课题号:41201275);国家科技支撑计划项目(课题号:2011BAD31B03);中国科学院西部行动计划(课题号:KZCX2-XB3-09)~~

摘　　要：顺坡垄作是在长江上游特别是紫色土坡耕地上农民普遍采用的耕作模式,以往由于主流思想的影响,没有得到应有的重视。以三峡库区紫色土坡耕地为例,采用野外调查与小区实验相结合,分别采集垄沟和垄坡表层土壤,测试顺坡垄作地块沟、垄土壤容重、粒径分布、有机质含量、TN、TP、土壤含水量等指标,小区实验调查顺坡垄作条件下的土壤流失特征,进而探讨顺坡垄作导致的土壤特性差异与顺坡垄作的水土保持机制。结果表明:与垄沟内土壤相比,垄坡土壤平均含水量、容重分别降低29.74%和16.41%,土壤总孔隙度高20.56%,说明垄坡土壤具有更大的吸持水分的潜力,降雨产流阈值相比于垄沟土壤也更大。相比于垄沟内土壤,粘粒在垄沟内发生富集,垄坡土壤中的有机质、总氮(TN)和总磷(TP)指标分别高18.79%、17.30%和9.31%。侵蚀泥沙中沙粒含量出现明显富集,几乎是垄沟土壤沙粒含量的1倍,而粘粒和粉粒含量则远小于径流小区土壤成分,说明顺坡垄作有利于<50μm土壤细颗粒的保持。侵蚀泥沙中有机质和TN远小于径流小区土壤成分,而TP则高于径流小区土壤成分,与侵蚀泥沙颗粒分选现象近似,说明顺坡垄作的肥力指标流失差异同样主要由侵蚀分选导致,也说明顺坡垄作有利于紫色土有机质和氮肥的保持。Although down-slope tillage was used to practice on purple soil sloping farmland in the upper reach of Yangtze River,fewer details were investigated in past decades. This study focus on down-slope tillage on purple soil sloping farmland in the Three Gorges Reservoir Regions,the field investigate method and runoff plot method were utilized to survey scales of down-slope furrow,soil density,soil particle distribution,TOC,TN,TP and water content. The results displayed that,compared with down-slope furrow,soil water content and soil density in the furrow slope were less than 29. 74% and 16. 41%,but the soil total porosity was more than 20. 56%. Clay particles were enriched in the down-slope furrows,the TOC,TN and TP contents in furrow slope soil were more than18. 79%,17. 30% and 9. 31%,respectively. Sand particles were enriched double in sediment,but clay particles and silt particles contents in sediment were less compared with plot soil,it was implied that the down-slope furrow tillage method contributed 〉50μm fine particles to be conservation. TOC and TN contents in sediment were fewer than in the plot soil,and this trend was similar to fine particles,it was illustrated the down-slope furrow tillage method contributed TOC and TN conservation too.

关 键 词：紫色土 陡坡耕地 顺坡垄作 水土保持 

分 类 号：S155.25[农业科学—土壤学] S157.1[农业科学—农业基础科学]