Mitigating diffuse phosphorus transfer from agriculture according to cost and efficiency.

Area of Science:

• Environmental Science
• Agricultural Science
• Water Quality Management

Background:

• Phosphorus (P) transfer from agriculture to water bodies is a significant environmental concern in England and Wales (E&W).
• Effective mitigation strategies are needed to reduce P pollution and its impact on aquatic ecosystems.

Purpose of the Study:

• To collate and assess potential options for mitigating phosphorus transfer from diverse farm systems in E&W.
• To evaluate the effectiveness of these options in reducing P mass transfer and their associated costs to the farming industry.

Main Methods:

• Utilized a simple model framework (PEASE) to identify mitigation methods across three categories: input reduction, mobilization prevention, and transport control.
• Assessed 15 methods for mitigating P inputs, 19 for preventing P mobilization, and six for controlling P transport.
• Analyzed cost-effectiveness and cumulative P reduction potential for different farm systems.

Main Results:

• Largest reductions in P inputs were observed in grassland and horticulture.
• Transport mitigation methods showed larger P transfer reductions (up to 2.2 kg P ha(-1)) than input or mobilization methods.
• Buffer zones and constructed wetlands were identified as highly effective, with buffer zones being very cost-effective ( £3-5 kg(-1) P saved).
• Specific cumulative P reduction targets were identified for different farm systems (e.g., 0.2 kg ha(-1) for uplands, 2.2 kg ha(-1) for arable).

Conclusions:

• Established catchment-scale evidence for mitigation is sparse, particularly for specific farm systems in E&W.
• The PEASE model provides a useful framework for prioritizing cost-effective P mitigation options.
• Further research is needed to address uncertainties and validate findings across different farm systems.