模拟雨强和地下裂隙对喀斯特地区坡耕地养分流失的影响

发布时间：2018-06-01 21:40

本文选题：养分 + 产流　；参考：《农业工程学报》2017年02期

【摘要】：喀斯特坡面水土地下漏失直接观测难度大,其土壤养分地下漏失的研究仍处于空白,而雨强和地下孔(裂)隙度(以下简称地下裂隙)对其土壤养分流失影响作用尚不清楚。该文以喀斯特坡耕地为研究对象,通过模拟其地表微地貌及地下裂隙构造特征,采用人工模拟降雨试验研究雨强和地下裂隙对喀斯特坡面氮磷钾养分流失的影响。结果表明:雨强对地表产流产沙影响显著(P0.05),其产流产沙量均随雨强增大而增加,且地表产流产沙临界雨强在30~50 mm/h之间;雨强对地表径流各养分输出负荷、地下径流全氮(TN)输出负荷及径流TN总负荷影响亦显著(P0.05)。地下裂隙度对地下径流TN输出负荷影响显著(P0.05),而总体上对其产流产沙、地表径流泥沙各养分输出负荷及总负荷影响不明显。喀斯特坡面TN、全磷(TP)输出负荷总体以径流为主,而全钾(TK)输出负荷则以泥沙为主。雨强是喀斯特坡面土壤养分流失的重要影响因子,地下裂隙度对其养分流失影响不大,但地下径流是喀斯特坡面主要的养分流失方式。研究结果可为喀斯特坡耕地养分流失的机理揭示及源头控制提供基本参数和科学依据。
[Abstract]:It is difficult to observe soil and water loss directly on karst slope, and the study of soil nutrient loss is still blank, but the effect of rain intensity and underground pore (crack) on soil nutrient loss is not clear. In this paper, the effects of rainfall intensity and underground fissures on the loss of nitrogen, phosphorus and potassium in karst sloping land were studied by simulating the surface microgeomorphology and the structural characteristics of underground fissures. The results showed that rain intensity had a significant effect on surface runoff and sediment yield (P0.05), and the runoff and sediment yield increased with the increase of rainfall intensity, and the critical rainfall intensity of surface runoff sediment yield was between 30 ~ 50 mm/h, and the rainfall intensity had a significant effect on the nutrient output load of surface runoff. The effects of total nitrogen (TNN) output load and total runoff TN load on total nitrogen (TNN) in underground runoff were also significant (P 0.05). The influence of underground fissure degree on TN output load of underground runoff was significant (P 0.05), but on the whole, the effect of runoff and sediment on the output load and total load of nutrients from surface runoff and sediment was not obvious. On the karst slope, the output load of total phosphorus (TP) is mainly runoff, while the output load of total potassium (TK) is sediment. Rainfall intensity is an important factor affecting soil nutrient loss on karst slope. Underground fissure degree has little effect on nutrient loss, but underground runoff is the main nutrient loss mode in karst slope. The results can provide basic parameters and scientific basis for revealing the mechanism of nutrient loss and controlling the source of nutrient loss in karst sloping farmland.
【作者单位】：贵州大学林学院;
【基金】：国家重点研发计划课题(2016YFC0502604) 国家自然科学基金项目(41671275,41461057) 贵州省应用基础重大专项(黔科合JZ字[2014]2002)
【分类号】：S157

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