水蚀过程中裸露陡坡耕地土壤侵蚀特征  

Soil and Water Loss on the Tilled Bare Land with Steep Slope in Rainfall-Erosion Processes

作　　者：赵龙山[1,2] 侯瑞[1] 吴发启[2] 戴全厚[1] ZHAO Longshan1,2 , HOU Rui1 , WU Faqi2, DAI Quanhou1(1. College of Forestry, Guizhou University, Guiyang 550025 ; 2. College of Natural Resources and Environment, Northwest A＆ F University, Yangling , Shaanxi 71210)

机构地区：[1]贵州大学林学院,贵阳550025 [2]西北农林科技大学资源环境学院,陕西杨凌712100

出　　处：《水土保持学报》2018年第1期74-79,共6页Journal of Soil and Water Conservation

基　　金：国家自然科学基金项目(41601293);贵州省科技计划项目(黔科合基础[2016]1027;黔科合[2016]支撑2835号);贵州省教育厅青年科技人才成长项目(黔教合KY字[2016]114);贵州省国内一流学科建设项目(GNYL[2017]007)

摘　　要：在坡耕地上,农业耕作措施改变了地表微地形,对坡地土壤侵蚀过程产生影响。深入了解耕作措施对坡地土壤侵蚀的影响,以便为开展陡坡耕地退耕还林(草)工程的水土保持效益评价提供科学依据。以30°陡坡耕地为研究对象,采用室内人工模拟降雨试验方法,对采用人工锄耕、人工掏挖和等高耕作的裸坡地土壤侵蚀特征进行研究。用相同坡度平整坡地作为对照措施。降雨强度为60,90,120mm/h,降雨历时80min。结果表明:(1)在陡坡耕地上,在雨强为60,90mm/h时,3种耕作措施都具有延缓坡地产流的作用,但在雨强为120mm/h时,人工锄耕和人工掏挖坡地产流开始时间与平整坡地无显著差异(P>0.05);(2)对采用等高耕作的陡坡地,在3个降雨强度下,累计产流量均低于平整坡地,但采用人工锄耕和人工掏挖的陡坡地与平整坡地相比并无明显规律;(3)在降雨强度为120mm/h时,耕作陡坡地地表径流含沙量较高,土壤侵蚀量是平整坡地的2~5倍。因此,在裸露陡坡耕地上,当降雨强度偏大时,采用农业耕作措施不仅不能降低土壤侵蚀发生,反而会增加。Tillage practices,which change the soil surface structure,lead to different soil erosion characteristics on the tilled surfaces compared to the smooth surface.The objective of this study was to analyze soil and water loss on the tilled surfaces in rainfall-erosion processes based on the simulated rainfall experiments.Experiment results would be used for evaluating the soil and water conservation benefit of the projects of return steep slope land to forestry.Tillage practices in this study included shallow hoeing（SH）,deep hoeing（DH）and contour ploughing（CP）.A smooth surface（SS）was served as control measure.Rainfall intensities were 60,90 and 120 mm/h and rainfall duration was 80 min for three rainfall intensities.Results showed that：（1）On the tilled steep slope,three tillage practices delayed the beginning of surface runoff during the rainfall of 60 and 90 mm/h intensities,but no significant difference was found in surface runoff initiation time between SH and SS,and between DH and SS during the rainfall of 120 mm/h intensity;（2）The cumulative production flow of CP was lower than the SS under three rainfall intensities,but no obvious regularity in size of the cumulative production flow for SH and DH treatments compared with SS;（3）In rainfall of 120 mm/h intensity,the flow sediment concentration of slope with tillage practices was higher than SS,leading soil sediment from three tilled slopes was 2~5 times of SS.Therefore,on the tilled and bare steep slope,when the rainfall intensity is larger,the tillage practices not only fail to reduce soil erosion,instead will increase.

关 键 词：地表糙度 耕作措施 坡耕地 土壤侵蚀 

分 类 号：S157.2[农业科学—土壤学]