The management of farm nitrate leaching in Poole Harbour

Farmers in Poole Harbour are subject to more scrutiny of their inputs than virtually anywhere else in the country. This has led to frustration and collaboration in equal parts as they work together to face the issues in the region. However, as a surveyor once quite involved with the trading of intangible assets, the harbour is currently a very interesting place indeed.

Poole Harbour is a Special Protection Area. It is deemed by the ecological community to be in generally poor condition. This is deemed to be due to excessive nitrate leaching into the waters of the Harbour and rivers feeding it. Sources of nitrate leaching include sewage processing, development and agriculture. Developers and water companies face their own restrictions here; this blog will focus on agriculture.

In 2015, the Worldwide Fund for Nature (WWF) launched a judicial review claiming that the Department for Environment Food and Rural Affairs (Defra) was not meeting its obligations to protect the Harbour. The WWF argued that the power to create a Water Protection Zone (WPZ) had not been considered.

A WPZ would mean the creation of detailed, potentially invasive site-specific secondary legislation. Defra said they preferred not to do this if other, less nuclear options might be effective. They suggested that pursuing these softer options would also help prepare for a WPZ if one were needed.

Thus a settlement was reached in which Defra via the Environment Agency (EA), to whom many relevant powers are delegated, would prepare a technical document laying out with scientific background what these measures would be. If a given measure is found to be ineffective, the next in the sequence is then pursued.

The current measure is a combination for tighter enforcement of existing regulations plus a scheme in which farmers record their nitrogen inputs and any mitigations they are taking. This recording is done by completing spreadsheet called the “Nitrate Leaching Tool” (NLT). If the figure shown on the NLT is more than the annual target (which will reduce year-on-year until reaching 18.1kg/ha in 2030), the EA says the farm in question may be penalised.

How much nitrate leaching is occurring varies greatly between farms. It is usually lowest for extensive pasture farms and highest for conventional arable farms, with mixed farms, dairies and others falling between.

To account for this, a trading system is being introduced by the sector. This will allow farms with higher leaching figures to annually purchase offsets from those with lower ones. In this way all farms are incentivised to reduce their leaching.

Following excellent buy-in from farmers in the catchment, the first round of NLTs sent in last year showed leaching across the catchment to already be less than the 18.1kg/ha long-term target. The EA has however since cited double counting issues within the NLT. As a result a new committee of independent experts has been set up to scrutinise the NLT.

The NLT need not be limited to Poole Harbour – it could be useful anywhere farm nutrient leaching needs to be measured. Moreover, the trading system could theoretically be used on similar sites across the country. Therefore, work occurring here is of potentially national significance.

The CLA feeds back to the EA via the Poole Harbour Nutrient Management Scheme Project Group. We have also attended a ministerial visit on the subject, and will be visiting a number of affected members later this month.

While the government’s hand has been somewhat forced here by the courts, regulation must be no more burdensome than absolutely necessary. We will therefore continue our engagement in this area.

The CLA South West recently held at webinar with Louise Stratton, the Development Manager of the Poole Harbour Nutrient Management Scheme. You can watch it here.