Contributions of Systematic Tile Drainage to Watershed-Scale Phosphorus Transport
Contributions of Systematic Tile Drainage to Watershed-Scale Phosphorus Transport
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DOI：
10.2134/jeq2014.04.0149
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发表时间：
2015-03-01
影响因子：
2.4
通讯作者：
Fausey, Norman R.
中科院分区：
文献类型：
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作者：
King, Kevin W.;Williams, Mark R.;Fausey, Norman R.
农田中的磷（P）迁移仍然是解决世界各地淡水系统中有害藻华和滋扰藻类问题的焦点。在潮湿，排水不良的地区，人们的注意力已经转向通过地下瓷砖排水的P输送。然而，瓷砖排水对流域尺度磷流失的贡献的研究是有限的。本研究的目的是评估长期的磷运动通过瓷砖排水和其表现在流域出口。排放数据和相关的P浓度收集了8年（2005-2012年），从六个瓷砖排水沟和上游大核桃溪流域内的上游流域在中部俄亥俄州的流域出口。结果表明，瓷砖排水占47%的排放量，48%的溶解P，和40%的总P输出的流域。流域的平均年总磷流失量为0.98 kg ha（-1），6个瓦片排水沟的年总磷流失量为0.48 kg ha（-1）。磷负荷瓦和流域排放往往是在冬季，春季和秋季较大，而P浓度最大的夏季。在8年的研究中，P在瓷砖排水沟中运输的所有测量浓度的90%超过了建议的水平（0.03毫克L-1），以尽量减少有害藻华和滋扰藻类。因此，本研究的结果表明，在系统的瓷砖排水的源头流域，通过瓷砖排水沟输送到地表沃茨的P量不能被解雇。鉴于磷损失量相对于典型的应用率，最佳管理实践（BMPs）的开发和实施必须共同考虑经济和环境效益。具体来说，实施BMP应集中在晚秋，冬季和早春季节时，大多数P负载发生。
Phosphorus (P) transport from agricultural fields continues to be a focal point for addressing harmful algal blooms and nuisance algae in freshwater systems throughout the world. In humid, poorly drained regions, attention has turned to P delivery through subsurface tile drainage. However, research on the contributions of tile drainage to watershed-scale P losses is limited. The objective of this study was to evaluate long-term P movement through tile drainage and its manifestation at the watershed outlet. Discharge data and associated P concentrations were collected for 8 yr (2005-2012) from six tile drains and from the watershed outlet of a headwater watershed within the Upper Big Walnut Creek watershed in central Ohio. Results showed that tile drainage accounted for 47% of the discharge, 48% of the dissolved P, and 40% of the total P exported from the watershed. Average annual total P loss from the watershed was 0.98 kg ha(-1), and annual total P loss from the six tile drains was 0.48 kg ha(-1). Phosphorus loads in tile and watershed discharge tended to be greater in the winter, spring, and fall, whereas P concentrations were greatest in the summer. Over the 8-yr study, P transported in tile drains represented 90% of all measured concentrations exceeded recommended levels (0.03 mg L-1) for minimizing harmful algal blooms and nuisance algae. Thus, the results of this study show that in systematically tile-drained headwater watersheds, the amount of P delivered to surface waters via tile drains cannot be dismissed. Given the amount of P loss relative to typical application rates, development and implementation of best management practices (BMPs) must jointly consider economic and environmental benefits. Specifically, implementation of BMPs should focus on late fall, winter, and early spring seasons when most P loading occurs.