• ISSN 1008-505X
  • CN 11-3996/S
黄俣晴, 陈婷婷, 李勇, 黄智刚, 黎静宜, 戴谅, 王旭, 郭豪, 刘小梅, 康振威. 流域沟渠植草拦截农田氮磷入河污染的有效性研究[J]. 植物营养与肥料学报, 2021, 27(11): 1993-2000. DOI: 10.11674/zwyf.2021462
引用本文: 黄俣晴, 陈婷婷, 李勇, 黄智刚, 黎静宜, 戴谅, 王旭, 郭豪, 刘小梅, 康振威. 流域沟渠植草拦截农田氮磷入河污染的有效性研究[J]. 植物营养与肥料学报, 2021, 27(11): 1993-2000. DOI: 10.11674/zwyf.2021462
HUANG Yu-qing, CHEN Ting-ting, LI Yong, HUANG Zhi-gang, LI Jing-yi, DAI Liang, WANG Xu, GUO Hao, LIU Xiao-mei, KANG Zhen-wei. Effectiveness of grass planting in drainage ditches to intercept nitrogen and phosphorus pollution from farmland into rivers[J]. Journal of Plant Nutrition and Fertilizers, 2021, 27(11): 1993-2000. DOI: 10.11674/zwyf.2021462
Citation: HUANG Yu-qing, CHEN Ting-ting, LI Yong, HUANG Zhi-gang, LI Jing-yi, DAI Liang, WANG Xu, GUO Hao, LIU Xiao-mei, KANG Zhen-wei. Effectiveness of grass planting in drainage ditches to intercept nitrogen and phosphorus pollution from farmland into rivers[J]. Journal of Plant Nutrition and Fertilizers, 2021, 27(11): 1993-2000. DOI: 10.11674/zwyf.2021462

流域沟渠植草拦截农田氮磷入河污染的有效性研究

Effectiveness of grass planting in drainage ditches to intercept nitrogen and phosphorus pollution from farmland into rivers

  • 摘要:
    目的 过度施肥与降雨径流的耦合作用使得大量氮磷从农田流失进入河道,导致河湖水体污染。在水土流失严重区,尤其是热带–亚热带集约化农业坡地,土层浅薄、蓄水性差,在降雨条件下所施肥料极易发生径流侵蚀流失,通过沟渠进入下游河湖水体,导致水体污染。如何控制这种水蚀型面源污染物从农田向河湖水体的输送愈来愈受到人们的关注,为此在流域下游沟渠构建植物拦截系统,评价其减少坡面氮磷入河污染的有效性,为水蚀型农田面源污染物的流域防控提供理论依据。
    方法 本研究在广西客兰水库水源区那辣小流域,选择下游500 m长的沟渠,该沟渠接收流域上游来水并直接输入水库,隔段种植当地优势植物狗牙根Cynodon dactylon (L.) Pers和象草(Pennisetum purpureum),以及引种植物香根草Vetiveria zizanioides (L.) Nash (于南宁花鸟市场购买香根草籽育苗移栽)。在13次降雨事件下分别采集沟渠入口和出口处的水样进行检测,用以研究面源污染防治效益。
    结果 与流域上游入口比较,下游植草沟渠输出水体中溶解态总氮(TDN)浓度由17.55 mg/L降至12.43 mg/L,NH4+-N由1.06 mg/L降至0.73 mg/L,NO3-N浓度由15.10 mg/L降至10.92 mg/L,溶解态总磷(TDP)浓度由0.031 mg/L降至0.021 mg/L;植物对降雨事件下流域输入沟渠中的TDN、NH4+-N、NO3-N和TDP平均去除率分别为31.90%、27.92%、29.80%和31.02%。
    结论 在热带和亚热带集约化径流农业流域,选择连接上游坡地与下游河湖水库的沟渠植草,可以对流域流失氮磷实施有效地拦截和去除,是一个简单、可行、有效的农业面源污染流域防控措施,值得推广应用。

     

    Abstract:
    Objectives The coupling effect of excessive fertilization with rainfall runoff causes a large amount of nitrogen and phosphorus loss from farmland into river channels, resulting in water pollution of rivers and lakes. This effect is very severe in the intensive agricultural sloping lands with shallow soil layer and poor water storage of tropics and subtropics. Under rainfall events, the fertilizer will be more easily lost from slopping land and transported to rivers and lakes through ditches, resulting in water pollution downstream. How to control the transport of this non-point source pollutants derived from farmland erosion to rivers and lakes has attracted more and more attention. Therefore, a plant interception system was constructed in the downstream ditches of watershed, and the effectiveness of this system was evaluated in term of reduction of nitrogen and phosphorus pollutants passed through this plant interception system. It is expected that this study can provide a theoretical basis for the control of water erosion-induced agricultural non-point source pollutants in the watershed.
    Methods In this study, a 500 meters long ditch in the downstream was selected in Nala small watershed, located in the water source area of Kelan Reservoir, Guangxi. This ditch collects the water of the upper watershed and directly transport to the reservoir. The dominant plants, Cynodon dactylon (L.) Pers and Pennisetum purpureum, and the introduced plant Vetiveria zizanioides (L.) Nash, transplanting from a Nanning Market, Guangxi, were planted spacing out in the ditch. Water samples were collected from inlet and outlet of ditch, respectively, for testing at 13 rainfall events, and the benefits of planted grasses in controlling non-point source pollution ware investigated.
    Results Compared with the upstream inlet of watershed, the concentration of dissolved total nitrogen (TDN) in the downstream outlet of the vegetated ditches decreased from 17.55 mg/L to 12.43 mg/L, and NH4+-N decreased from 1.06 mg/L to 0.73 mg/L. NO3-N concentration decreased from 15.10 mg/L to 10.92 mg/L, and dissolved total phosphorus (TDP) decreased from 0.031 mg/L to 0.021 mg/L. The average removal rates of TDN, NH4+-N, NO3-N and TDP from watershed input ditches under rainfall events by plants were 31.90%, 27.92%, 29.80% and 31.02%, respectively.
    Conclusions The results showed that in the intensive multi-runoff agricultural watershed of tropical and subtropical regions, grass planting in ditches linking upstream slopes with downstream rivers or lakes can effectively intercept and remove nitrogen and phosphorus runoff. This measure is a simple, feasible and effective approach for preventing and controlling agricultural non-point source pollution in small watershed, and is worthy of popularization and application.

     

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