人工降雨条件下植被覆盖对黄土坡面养分随径流泥沙迁移影响的试验研究  

Experimental Study on the Influence of Vegetation Cover on Loess Slope Surface Nutrient Transport Along with Runoff and Sediment Under Artificial Rainfall

作　　者：李家明 汪建芳 杨艳芬 王兵[1,2,3] LI Jiaming;WANG Jianfang;YANG Yanfen;WANG Bing(Research Center for Soil and Water Conservation and Ecological Environment,Ministry of Education,Chinese Academy of Sciences,Yangling,Shaanxi 712100;State Key Laboratory of Soil Erosion and Agriculture on the Loess Plateau,Northwest A&F University,Yangling,Shaanxi 712100;University of Chinese Academy of Sciences,Beijing 100049)

机构地区：[1]中国科学院教育部水土保持与生态环境研究中心,陕西杨凌712100 [2]西北农林科技大学黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100 [3]中国科学院大学,北京100049

出　　处：《水土保持学报》2021年第4期7-13,共7页Journal of Soil and Water Conservation

基　　金：国家重点研发计划项目“黄土高原区域生态系统演变规律和维持机制研究”(2016YFC0501603),“黄土丘陵沟壑区植被功能提升与山地果园管理关键技术及示范”(2016YFC0501703),中国科学院西部青年学者项目“黄土高原退耕草地近地表特征变化及其对土壤侵蚀过程的影响”(XAB2019A04)。

摘　　要：植被覆盖可有效保护地表,抑制产流产沙过程,进而影响坡面养分迁移过程。选取黄土高原典型白羊草和铁杆蒿草地,通过人工模拟降雨试验(雨强60 mm/h,历时60 min,坡度15°),研究植被不同盖度下(10%,20%,30%,45%,60%,80%)坡面径流、泥沙养分特征。结果表明:(1)土壤有机质、全氮和全磷含量均随植被盖度增加呈线性增加(R^(2)≥0.63),相对于铁杆蒿样地,白羊草样地土壤有机质和全磷含量分别增加28.8%~107.1%和10.6%~25.0%,全氮含量减少2.6%~42.5%。(2)径流中有机质、全氮和全磷浓度随植被盖度的增加而减少0.6%~63.7%,但种间差异不显著(P>0.05)。径流中有机质、全氮和全磷量随植被盖度的增加显著降低1.9%~83.9%,且当植被盖度≥20%时,白羊草样地径流中有机质、全氮和全磷的量较铁杆蒿分别显著减少28.4%~66.4%,10.7%~55.8%和3.3%~64.7%。(3)泥沙中有机质、全氮和全磷的量随植被盖度的增加减幅为-59.5%~65.1%,平均减少5.8%,其泥沙中养分的含量白羊草总体低于铁杆蒿。白羊草和铁杆蒿泥沙有机质、全氮和全磷的量随盖度增加分别呈指数函数(R^(2)≥0.78)和先增后减的下降趋势,其泥沙中养分的量显著减少69.9%~99.3%。(4)白羊草和铁杆蒿样地径流泥沙中有机质、全氮和全磷总量随植被盖度增加分别呈指数函数(R^(2)≥0.53)和先增后减的下降趋势,且当植被盖度≥45%时,白羊草有机质、全氮和全磷总量较铁杆蒿样地分别减少33.7%~71.8%,50.1%~53.6%和48.1%~64.3%。(5)白羊草和铁杆蒿样地泥沙中有机质、全氮和全磷富集比随盖度的增加呈线性降低(R^(2)≥0.56)。2种植被土壤有机质和全磷主要随泥沙迁移为主,土壤全氮主要以径流迁移为主。研究成果为植被覆盖影响坡面养分迁移机制提供理论参考。Vegetation cover can effectively protect the ground surface,inhibit the process of runoff and sediment production,and then affect the process of nutrient migration on slopes.Typical Bothriochloa ischaemum and Artemisia gmelini grasslands in the Loess Plateau were selected and simulated rainfall experiments(rain intensity 60 mm/h,duration 60 min,slope 15°)were used to study the slope runoff and sediment nutrient characteristics under different coverage conditions(10%,20%,30%,45%,60%,80%).The results showed that:(1)The contents of soil organic matter,total nitrogen and total phosphorus increased linearly with the increase of coverage(R^(2)≥0.63).Compared with Artemisia gmelini plot,the contents of soil organic matter and total phosphorus in Bothriochloa ischaemum plot increased by 28.8%~107.1% and 10.6%~25.0% respectively,while the contents of total nitrogen decreased by 2.6%~42.5%.(2)With the increase of vegetation coverage,the concentrations of organic matter,total nitrogen and total phosphorus in runoff decreased by 0.6%~63.7%,but there was no significant difference between the two species(P>0.05).The amount of organic matter,total nitrogen and total phosphorus in runoff decreased by 1.9%~83.9%,and when vegetation coverage was ≥20%,the amount of organic matter,total nitrogen and total phosphorus in runoff in Bothriochloa ischaemum sample decreased by 28.4%~66.4%,10.7%~55.8% and 3.3%~64.7%,respectively,compared with Artemisia gmelini sample.(3)The contents of organic matter,total nitrogen and total phosphorus in the sediment decreased by -59.5%~65.1% with the increase of vegetation coverage,with an average decrease of 5.8%.The nutrients amount of the sediment Bothriochloa ischaemum were generally lower than those of Artemisia gmelini.The amount of Bothriochloa ischaemum and Artemisia gmelini sediment organic matter,total nitrogen and total phosphorus showed an exponential function(R^(2)≥0.78)and a downward trend with the increase in coverage,respectively.The nutrients amount in the sediment were significan

关 键 词：黄土坡面 人工降雨 植被盖度 径流泥沙养分 养分迁移 

分 类 号：S157[农业科学—土壤学]