喀斯特裸露坡耕地径流养分流失试验研究  

Experimental Study about Runoff Nutrient Loss on Karst Bare Slope

作　　者：靳丽[1] 戴全厚[1] 李昌兰[1] 彭旭东[1] 严友进 

机构地区：[1]贵州大学林学院,贵阳550025

出　　处：《水土保持学报》2016年第5期46-51,57,共7页Journal of Soil and Water Conservation

基　　金：国家自然科学基金项目(41461057;41061029);贵州省重大专项(黔科合JZ字[2014]2002)

摘　　要：为揭示雨强对喀斯特坡耕地养分流失的影响,运用可调坡度、地下孔(裂)隙度试验钢槽装填土石模拟喀斯特裸露坡耕地,采用人工模拟降雨的方法研究不同雨强下喀斯特裸坡径流养分流失特征。结果表明:(1)雨强为15,30mm/h时地表不产流,雨强为50mm/h时地表有产流;试验雨强下地下孔(裂)隙均有径流产生。(2)地表径流中全氮和全钾流失量均随雨强增大而增大,全磷流失量则先增大后减小;地下径流中全氮流失量随雨强增大呈先增大后减小趋势,全钾流失量与雨强正相关,全磷流失量与雨强关系不明显。(3)雨强为30,50mm/h时养分以地下孔(裂)隙流失为主,其贡献率为100%;地下径流中全氮流失量对其总流失量的贡献率表现为:15mm/h>30mm/h>50mm/h>70mm/h>90mm/h,全磷与全钾为:15mm/h>30mm/h>50mm/h>90mm/h>70mm/h。(4)地表径流量、全氮、全钾流失量和地下全钾流失量与雨强均呈显著正相关,相关系数分别为0.926,0.919,0.982和0.955。15,30mm/h雨强下,径流养分仅通过地下孔(裂)隙流失,50mm/h及以上雨强时养分伴以地表径流流失,且地下流失量大于地表流失量。In order to reveal the influence of rain intensity on nutrient losses from Karst bare slope,characteristics of runoff nutrient loss on Karst bare slope under different rainfall intensities were studied through artificial rainfall experiments based on simulating Karst bare slope in a steel tank with the adjustable slope and degree of underground holes（cracks）.In each experiment,the tank was filled with soils and rocks.Results indicated：（1）Surface runoff didn＇t generated on karst bare slope under 15mm/h and 30mm/h rainfall intensities,however,the surface runoff was yielded when rainfall intensity increased to 50mm/h,and the underground holes（cracks）produced runoff under any rainfall intensity.（2）In the case of surface runoff,the amount of total nitrogen（TN）and total potassium（TK）loss increased with the rainfall intensity,however,the amount of total phosphorus（TP）loss first increased and then decreased,in the case of underground holes（cracks）runoff,the amount of TN loss first increased and then decreased with the rainfall intensity increasing,the amount of TK loss was positive correlation with rainfall intensities while the amount of TP loss was insignificant correlation with the rainfall intensity.（3）When rainfall intensities were 30 mm/h and 50mm/h,the nutrient loss was dominated by underground hole（crack）loss,and its contribution was 100%,the contribution of TN loss in underground hole（crack）runoff presented the order as 15mm/h30mm/h50mm/h70mm/h90mm/h,and the order of TP and TK was 15mm/h30mm/h50mm/h90mm/h70mm/h.（4）Both the runoff volume,TN loss,TK loss in surface runoff and the TK loss in underground holes（cracks）runoff had significant positive correlation with rainfall intensity and its correlation coefficient were 0.926,0.919,0.982 and 0.955 respectively.Runoff nutrients loss only through the underground holes（cracks）when the rainfall intensity was 15,30mm/h,as the rainfall intensity≥50mm/h,accompanied with surface runoff loss,and the amount of unde

关 键 词：养分流失 径流 地下孔(裂)隙 喀斯特裸坡 

分 类 号：S157.1[农业科学—土壤学]