地表覆盖对紫色土坡耕地壤中流流动和硝态氮运移过程的影响  

Effects of Surface Mulching on Interflow and Nitrate Migration Process in a Sloping Farmland of Purple Soil

作　　者：龙天渝[1,2] 刘金辉 刘祥章 曹怀亮[1] 田大浪 LONG Tianyu;LIU Jinhui;LIU Xiangzhang;CAO Huailiang;TIAN Dalang(Key Laboratory of Eco-environment of Three Gorges Region of Ministry of Education,Chongqing University, Chongqing 400045,China;National Centre for International Research of Low-Carbon and Green Buildings,Chongqing University,Chongqing 400045,China;School of Civil Engineering,Chongqing University,Chongqing 400045,China)

机构地区：[1]重庆大学三峡库区生态环境教育部重点实验室,重庆400045 [2]重庆大学低碳绿色建筑国际联合研究中心,重庆400045 [3]重庆大学土木工程学院,重庆400045

出　　处：《水土保持研究》2018年第6期68-73,共6页Research of Soil and Water Conservation

基　　金："十二五"国家科技支撑计划重点项目(2011BAD31B03)

摘　　要：针对不同坡度下的表土结皮和稻草覆盖两种地表状况下的紫色土坡耕地,构建养分淋失的三维对流—弥散模型,数值模拟坡耕地中水分和硝态氮浓度的时空分布,研究不同地表覆盖对紫色土坡耕地壤中流流动和硝态氮运移过程的影响。结果表明:表土结皮通过减少水分入渗使壤中流流量与稳定强度降低,硝态氮随壤中流流失量减少,而稻草覆盖下的情况正好相反;在降雨强度为30mm/h、降雨历时为3h,坡度分别为5°,10°,15°,20°和25°的情况下,结皮使壤中流流量降低34.8%～43.0%,硝态氮随壤中流流失量减少8.6%～34.4%,而稻草覆盖下壤中流出流量增加8.6%～12.6%,硝态氮随壤中流流失量增加8.6%～15.4%。对于紫色土坡耕地,在采用稻草覆盖增加入渗的情况下,应采取相应的措施保水保肥。For two kinds of surface conditions of sloping farmland of purple soil with topsoil crust and straw mulching under different slope gradients,the three-dimensional convective-dispersion model of nutrient leaching was established,the temporal and spatial distributions of interflow and nitrate concentration had been simulated numerically,and influences of surface mulching on interflow and nitrate migration process were studied.The results showed that,for topsoil crust,the rate and steady strength of interflow as well as the nitrate loss in the soil decreased due to reduction of water infiltration,while the situation for the straw mulch was opposite.For three hours rainfall with intensity of 30 mm/h,when slope gradients are 5°,10°,15°,20°and 25°,respectively,for topsoil crust,the rate at outlet decreased by 34.8%~43.0%,and the nitrate loss in the soil decreased by 8.6%~34.4%.However,for the straw mulch,the rate increased by 8.6%~12.6%,and the nitrate loss increased by 8.6%~15.4%.For the purple soil slope farmland,the appropriate measures should be taken to keep the water and fertilizer under the conditions of using straw mulch to increase infiltration.

关 键 词：坡耕地 硝态氮淋失 表土结皮 稻草覆盖 数值模拟 

分 类 号：X501[环境科学与工程—环境工程]