Phosphorous losses from farms 

As part of the Triple Axe Project, FWAG South West has been building a detailed evidence base to understand the root causes of phosphorus (P) losses from dairy farms in the River Axe catchment.

Getting to the root cause of phosphorous losses from farms 

This work underpins the project’s targeted support for farmers, helping them improve nutrient management, environmental compliance, and farm resilience.

How the evidence was built 

Over four years, FWAG South West’s Devon Nutrient and Soils team (FACTS and BASIS Soil and Water qualified advisers Samantha Read, Eve Halliday, and Dr Sabine McEwan) gathered extensive data across the catchment, including: 

• Soil sampling on 418 fields across 10 farms 

• Visual soil structure assessments on more than 700 fields 

• Calculation of 48 farm P balances and 17 P loadings 

• Review of nutrient and manure management plans with 100+ farmers 

This evidence informed a whole-farm approach that looks beyond surface-level fixes to address the full phosphorus cycle. 

Key insights 

• Livestock feed is the biggest contributor to excess phosphorus, making up 85.8% of P imports. 

• Most farms have a positive P balance, meaning they accumulate more P than they export. 

• Manure management planning often overlooks key factors like storage capacity, soil health, and spreading risk. 

• Soil P indices are unevenly distributed, with over 40% of fields above target levels, often near yards or in the most accessible areas. 

• Manure storage upgrades have significantly improved in the Axe catchment, but issues such as slurry storage limitations and planning delays hinder compliance with Storing Silage, Slurry and Agricultural Fuel Oil (SSAFO) and the Farming Rules for Water. 

What Triple Axe is doing 

Triple Axe is using this evidence to guide its delivery of: 

• Tailored advice to reduce P at source, especially in livestock feed. 

• Workshops and farmer engagement to improve nutrient planning. 

• Capital funding to support infrastructure upgrades and better slurry management. 

• Collaborative solutions that avoid ‘pollution swapping’ and support long-term farm sustainability.

By grounding its approach in robust data and field-level insights, Triple Axe is helping farmers make meaningful changes that benefit both their businesses and the River Axe’s water quality.