秸秆覆盖红壤径流养分流失效益及径流剪切力影响研究

发布时间：2018-02-08 08:59

本文关键词： 秸秆覆盖效益氮磷流失径流剪切力人工降雨　出处：《水土保持学报》2017年06期 　论文类型：期刊论文

【摘要】：采用模拟降雨试验的方法,研究秸秆覆盖条件下红壤侵蚀效益及动力影响因素。模拟降雨强度2.0mm/min,坡度20°,径流小区(长1.5m,宽0.5m,深0.3m)条件下,供试土壤为赤红壤。结果表明:(1)秸秆覆盖减流效益达到69.3%,减沙效益达到99.2%;明显提高土壤的入渗速率,渗透效益达到了32%,秸秆覆盖有较好的水土保持效益。(2)秸秆覆盖有效减少径流总氮、径流溶解态氮、径流颗粒态氮、径流总磷、径流溶解态磷、径流颗粒态磷的流失,减少径流中氮流失效益均达到74%以上,减少径流中磷流失效益均达到78%以上,径流中元素流失均以溶解态氮磷元素大于颗粒态氮磷元素,秸秆覆盖减少径流中磷养分流失的效益大于氮养分的流失效益。(3)建立单位面积单位时间径流剪切力和产沙率、径流总氮、径流溶解态氮、径流颗粒态氮和径流总磷、径流溶解态磷、径流颗粒态磷流失速率的模型,初步推断径流剪切力是土壤侵蚀的主要动力因素。(4)秸秆覆盖和未覆盖的临界启动径流剪切力分别为2.8N/m2和1.5N/m2。
[Abstract]:The effects of straw mulching on red soil erosion efficiency and dynamic factors were studied by simulated rainfall experiment under the condition of simulated rainfall intensity 2.0 mm / min, slope 20 掳, runoff plot (length 1.5 m, width 0.5 m, depth 0.3 m), and simulated rainfall intensity 2.0 mm / min, slope 20 掳, runoff plot (1.5 m long, 0.5 m wide, 0.3 m deep). The results showed that the benefit of straw mulching and sediment reduction was 69.3 and 99.2 respectively, and the infiltration rate of soil was increased obviously. The effect of straw mulch on soil and water conservation was 32. The straw mulch could effectively reduce the loss of total nitrogen, dissolved nitrogen, granular nitrogen, total phosphorus, dissolved phosphorus and granular phosphorus in runoff. The benefit of reducing nitrogen loss in runoff is more than 74%, and that of phosphorus loss in runoff is above 78%. Dissolved nitrogen and phosphorus elements are higher than granular nitrogen and phosphorus elements in runoff. The benefit of straw mulching in reducing phosphorus loss in runoff was greater than that in nitrogen loss. 3) Shear stress and sediment yield per unit area per unit time runoff, total nitrogen in runoff, dissolved nitrogen in runoff, granular nitrogen in runoff and total phosphorus in runoff were established. Based on the model of runoff dissolved phosphorus and runoff particle phosphorus loss rate, it is preliminarily deduced that runoff shear stress is the main dynamic factor of soil erosion.) the critical initial runoff shear stress of straw mulching and unmulched runoff is 2.8 N / m ~ 2 and 1.5 N / m ~ 2, respectively.
【作者单位】：福建师范大学地理科学学院;福建省亚热带资源与环境重点实验室;
【分类号】：S157

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