Mitigating Diffuse Phosphorus Transfer from Agriculture According to Cost and Efficiency

• Published in: Journal of environmental quality Vol. 38; no. 5; pp. 2012 - 2022
• Main Authors: Haygarth, P.M, ApSimon, H, Betson, M, Harris, D, Hodgkinson, R, Withers, P.J.A
• Format: Journal Article
• Language: English
• Published: Madison American Society of Agronomy, Crop Science Society of America, Soil Science Society 01.09.2009; American Society of Agronomy
• Subjects: agricultural land; Agricultural production; Agriculture; Artificial wetlands; Catchment scale; Consolidation; constructed wetlands; cost analysis; Cost engineering; Costs and Cost Analysis; dairy farming; Dairy farms; Dairy products; Decision support systems; diffusion; economic impact; Environmental Restoration and Remediation - economics; Environmental Restoration and Remediation - methods; eutrophication; Farming; Farming systems; Farms; Fertilizers; Grasslands; horticultural crops; Horticulture; leaching; livestock production; losses from soil; Mathematical models; Methods; nonpoint source pollution; nutrient management; Phosphorus; Phosphorus - analysis; Phosphorus - chemistry; pollution control; Reduction; riparian buffers; simulation models; streams; surface water; swine; Transport; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - chemistry; water pollution; Water Pollution, Chemical - prevention & control; Wetlands; England; Wales; British Isles, England; British Isles, Wales
• ISSN: 0047-2425; 1537-2537
• DOI: 10.2134/jeq2008.0102

Potential options for mitigating phosphorus (P) transfer from agriculture to water in England and Wales (E&W) were collated across a range of farm systems to assess their potential effectiveness in reducing mass of P transferred and potential cost (pounds sterling [£]) to the farming industry. A simple model framework (called PEASE) incorporating a number of assumptions was used to identify 15 methods for mitigating inputs of P to agricultural systems, 19 methods for preventing mobilization of P, and six methods for controlling the transport of P to streams. The scope for largest reductions in P inputs was to grassland and horticulture. Potential reductions in P mobilization were up to 1.2 kg P ha-1. Reductions in P transfer associated with transport mitigation were larger than those associated with input and mobilization methods (up to 2.2 kg P ha-1). The largest estimated reductions were achieved by installing buffer zones and constructed wetlands, the former being very cost effective (£3-5 kg-1 P saved). Plots of cost curves helped identify where the combined and cumulative P transfer reductions were attainable; these were approximately 0.2 kg ha-1 for uplands, 0.6 kg ha-1 for outdoor pigs, 0.9 kg ha-1 for intensive dairy, and 2.2 kg ha-1 for arable examples. We concluded that established catchment-scale evidence for mitigation is sparse, especially for specific farm systems in E&W. Sensitivities and uncertainties in the approach, especially associated with expert coefficients, are noted. This approach is nonetheless considered useful for prioritizing where and how best options might be most effectively targeted for least cost but greatest benefit.