Lancaster University, Lancaster, UK.
J Environ Qual. 2012 Mar-Apr;41(2):389-99. doi: 10.2134/jeq2010.0543.
Diffuse pollution remains a major threat to surface waters due to eutrophication caused by phosphorus (P) transfer from agricultural land. Vegetated buffer strips (VBSs) are increasingly used to mitigate diffuse P losses from agricultural land, having been shown to reduce particulate P transfer. However, retention of dissolved P (DP) has been lower, and in some cases VBSs have increased delivery to surface waters. The aims of this review were (i) to develop a conceptual model to enhance the understanding of VBS functioning in terms of DP, (ii) to identify key processes within the model that affect DP retention and delivery, and (iii) to explore evidence for the controls on these processes. A greater understanding in these areas will allow the development of management strategies that enhance DP retention. We found evidence of a surface layer in buffer strip soils that is enriched in soluble P compared with adjacent agricultural land and may be responsible for the reported increased DP delivery. Through increased biological activity in VBSs, plants and microorganisms may assimilate P from particulates retained in the VBSs or native soil P and remobilize this P in a more soluble form. These conclusions are based on a limited amount of research, and a better understanding of biogeochemical cycling of P in buffer strip soils is required.
由于磷（P）从农业用地转移导致富营养化，扩散污染仍然是地表水的主要威胁。植被缓冲带（VBS）越来越多地用于减轻农业用地的扩散 P 损失，已被证明可以减少颗粒 P 的转移。然而，溶解 P（DP）的保留率较低，在某些情况下，VBS 会增加向地表水的输送。本综述的目的是（i）建立一个概念模型，以增强对 VBS 在 DP 方面的功能的理解，（ii）确定模型中影响 DP 保留和输送的关键过程，以及（iii）探讨这些过程的控制因素。在这些领域有了更深入的了解，将能够制定出增强 DP 保留的管理策略。我们发现缓冲带土壤中的表层富含可溶性 P，与相邻的农业用地相比，这可能是报告中 DP 输送增加的原因。通过 VBS 中生物活性的增加，植物和微生物可能会从 VBS 或本地土壤 P 中保留的颗粒物质中吸收 P，并以更易溶解的形式重新释放 P。这些结论是基于有限的研究得出的，需要更好地了解缓冲带土壤中 P 的生物地球化学循环。
