How can farmers keep nutrients out of water?

Rising nitrogen and phosphorus concentrations in marine and freshwaters need to be addressed. They can be reversed by adopting farming practices which increase nutrient use efficiency and soil health, not just by de-intensifying productive agricultural systems. The total nutrient surplus generated by fertiliser and manure use on managed agricultural land in the UK remains high at 81kg/ha for nitrogen and 3.9kg/ha for phosphorus (Defra, 2018). There is scope for every farm business to be more efficient through reducing waste across the entire production cycle. If they do not, then further restrictions on nutrient use may be imposed from external sources such as government rules or market pressure. My study shows that there are many available technologies, including precision farming and nutrient recovery systems, to be harnessed to reduce nutrient loss.

These efforts should sit within a regulatory framework which takes the fairest and most proportionate rules from legislative approaches to improving water quality operating in New Zealand, the USA, Ireland, Denmark and the Netherlands. There are also lessons in how to achieve farmer ownership of solutions. Practical support for farmers to reduce nutrient surpluses must come from government, the supply chain, water companies and environmental organisations in the form of more focussed advice, research and training. Agricultural input suppliers could actively take a longer-term view and encourage more efficient use of their products by their farmer clients.

Financial assistance, to address investment, technical or skills gaps, needs to be channelled to farmers for adopting resource efficient farming practices. Funding can come from public and private sources in the form of annual payments, capital grants, loans and tax allowances, while the emerging markets for ecosystem services bringing in extra environmental investment from the private sector should not be ignored. Retailers and processors could, to their own business advantage as well, better reward farmer investment in resource efficient practices. Increasing slurry storage capacity on livestock farms to improve nutrient use and protect water quality is a high priority. Ultimately though it is down to farmers themselves to develop solutions for tackling nutrient enrichment of water and to implement the necessary changes, as groups of farmers in Wisconsin are doing.

All these steps will count for nothing if farmers do not realise the full potential of well-managed, fertile soils to hold onto nutrients, thereby increasing plant and animal performance and protecting water. Agriculture needs to move from nitrogen funded production back to a system which builds and utilises soil carbon. The examples given in this report of farmers in France, Iowa and Australia who are using conservation agriculture practices to build soil carbon demonstrate what a properly functioning soil can really look like, and what it can deliver for farmers, the environment and society.