冻融条件下土壤可蚀性对坡面氮磷流失的影响

发布时间：2018-04-06 00:24

本文选题：土壤含水率　切入点：侵蚀　出处：《农业工程学报》2017年24期

【摘要】：冻融作用与水力侵蚀的复合作用更容易使土壤发生侵蚀,进而加剧土壤养分的流失,为了揭示冻融作用下土壤可蚀性对坡面养分流失的影响,该文采用室内模拟降雨试验,研究了不同土壤含水率(SWC)下坡面的降雨产流产沙及养分流失特征,并分析了土壤可蚀性对坡面全氮(TN)和全磷(TP)流失的影响。结果表明:产流率与产沙率之间呈现正线性相关关系,相关方程斜率的绝对值可作为土壤可蚀性指标。径流中氮磷的流失主要受径流率控制,受土壤可蚀性影响较小(P0.05);而土壤可蚀性显著影响着泥沙中氮磷和总的氮磷流失(P0.01)。土壤可蚀性对黄土坡面氮素流失的影响与冻融作用有关,而土壤可蚀性对坡面磷素流失的影响与冻融作用无关,磷素的流失随着土壤可蚀性增加而增加。因此,在黄土地区,应当采取一系列的生态建设措施来控制水土流失,降低土壤可蚀性,从而减少坡面养分的流失。该研究结果为冻融条件下黄土坡面水-土和氮磷等养分流失机制提供了有效指导。
[Abstract]:The combined action of freeze-thaw and hydraulic erosion is more likely to cause soil erosion, and thus to aggravate the soil nutrient loss. In order to reveal the effect of soil erodibility on soil nutrient loss on slope surface under freezing and thawing, a simulated rainfall experiment was carried out in this paper.The characteristics of runoff and sediment yield and nutrient loss on slope surface with different soil moisture content (SWC) were studied, and the effects of soil erodibility on total nitrogen (TNN) and total phosphorus (TP) loss on slope surface were analyzed.The results showed that there was a positive linear correlation between runoff yield and sediment yield, and the absolute value of slope of correlation equation could be used as an index of soil erodibility.The loss of nitrogen and phosphorus in runoff was mainly controlled by runoff rate and was less affected by soil erodibility than that by soil erodibility, while soil erodibility significantly affected nitrogen and phosphorus loss and total nitrogen and phosphorus loss in sediment.The effect of soil erodibility on nitrogen loss on loess slope is related to freeze-thaw process, while the effect of soil erodibility on phosphorus loss is not related to freezing and thawing. Phosphorus loss increases with the increase of soil erodibility.Therefore, in loess region, a series of ecological construction measures should be taken to control soil erosion, reduce soil erodibility, and reduce nutrient loss on slope.The results provide effective guidance for the mechanism of nutrient loss, such as water-soil and nitrogen-phosphorus loss on loess slope under freezing and thawing conditions.
【作者单位】：西安理工大学西北旱区生态水利工程国家重点实验室培育基地;中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室;
【基金】：国家自然科学基金(Nos.41330858,41401316,41471226) 西安理工大学校基金(Nos.310-252071604)联合资助
【分类号】：S157.1

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