碎石含量对三峡库区坡耕地土壤氮磷流失特征的影响  

Effects of gravel contents on the soil nitrogen and phosphorus loss of sloping farmland in Three Gorges Reservoir of China

作　　者：赵冰琴 胡鑫凯[1] 高儒章 施伟豪 张兴凤 朱万庆 夏振尧 许文年[1,2] ZHAO Bingqin;HU Xinkai;GAO Ruzhang;SHI Weihao;ZHANG Xingfeng;ZHU Wanqing;XIA Zhenyao;XU Wennian(Key Laboratory of Geological Hazards on Three Gorges Reservoir Area(China Three Gorges University),Ministry of Education,Yichang 443002,China;Hubei Provincial Engineering Research Center of Slope Habitat Construction Technique Using Cement-based Materials(China Three Gorges University),Yichang 443002,China)

机构地区：[1]三峡库区地质灾害教育部重点实验室(三峡大学),宜昌443002 [2]水泥基生态修复技术湖北省工程研究中心(三峡大学),宜昌443002

出　　处：《农业工程学报》2024年第3期127-137,共11页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金项目(52200230);湖北省教育厅科学技术研究计划项目(Q20221210)。

摘　　要：坡耕地是三峡库区水土流失的主要来源,导致土壤养分的损失,严重影响库区生态环境建设与社会经济可持续发展。库区坡耕地土壤浅薄化和砾质化特征明显,但目前对含碎石坡耕地土壤侵蚀和养分流失特征的研究尚不多见。该研究通过设置3个降雨梯度(60、90、120 mm/h)和4种碎石含量(0、10%、20%、30%),开展人工模拟降雨试验,分析各试验条件下含碎石土壤产流产沙和氮磷流失特征。结果表明:1)碎石主要通过改变土壤结构以增大产流产沙量来促进氮磷流失,而对相应流失速率与流失浓度的变化规律影响较小,不同碎石含量下泥沙产量的变异系数更高,且泥沙中不同碎石含量下的氮磷流失量显著性差异更强(P<0.05);2)泥沙中累计磷流失量略微大于氮流失量,有效磷几乎不随泥沙流失,有效氮约占全氮流失量的15%;径流中氮素流失量几乎为磷素的10倍且以有效氮为主,占总氮流失量的75%,有效磷占总磷流失量的25%;3)不同碎石含量下有效氮流失规律大致相同,径流中硝态氮约占有效氮流失量的70%,而泥沙中则以铵态氮为主,约占65%;4)不同碎石含量下土壤中氮磷元素均以随侵蚀产沙流失为主,累计产沙量与氮磷元素随侵蚀产沙流失量均在20%碎石含量下达到极大值,10%碎石含量下流失量相对较小,因此泥沙库区坡耕地氮磷流失防治应以减少侵蚀产沙为主,注意大雨暴雨多发季节的水质监测与施肥控制。同时可对土中碎石进行清除使其保持在不高于10%水平。研究结果可为三峡库区含碎石坡耕地水土流失防治和氮磷流失治理提供科学参考。Sloping farmland is one of the most main sources of soil and water loss in the Three Gorges Reservoir area.A large number of soil nutrients are lost with soil erosion,especially nitrogen and phosphorus in the soil.Water eutrophication and secondary river pollution have posed a serious threat to the ecological environment and sustainable reservoirs.The sloping farmland soil in the Three Gorges Reservoir is also characterized by the outstanding shallow and gravelly.However,it is still lacking the soil erosion and nutrient loss of gravel-containing soil on sloping farmland.Taking the gravel-containing soil on sloping farmland as the research object,this study aims to clarify the effects of gravel content on the soil nitrogen and phosphorus loss of sloping farmland.Artificial simulated rainfall experiments were conducted at three rainfall intensities(60,90,and 120mm/h)and four gravel contents with different mass proportions(0,10%,20%,and 30%).The results indicated that the gravel promoted the runoff and sediment production by altering soil structure,thus increasing the nitrogen and phosphorus loss in soil.But there was also an outstanding effect on sediment yield.The runoff and sediment yield played an important intermediary role in the rainfall-induced soil nitrogen and phosphorus loss in the gravel-containing sloping farmland,although the primary pathway remained lost with the sediment.The gravel content was dominated by the low impact on the transform in the concentrations of nitrogen and phosphorus loss.The loss concentration under different gravel contents showed a trend of linear decline in a short period,and finally fluctuated within a small range.The higher coefficient of variation was found in the sediment yield under different gravel contents.There was also a more significant effect of gravel content on the nitrogen and phosphorus loss of sediment,compared with the runoff.Nitrogen and phosphorus were mainly lost with the sediment in the form of total phosphorus and nitrogen.The active components were accoun

关 键 词：土壤 侵蚀 碎石含量 雨强 产流产沙 氮磷流失 回归分析 

分 类 号：S157.1[农业科学—土壤学]