A study has found that Pembrokeshire farmers could save £1m a year on fertiliser while also helping to improve water quality in one of the UK’s most polluted river systems. The research says farms in the Cleddau catchment are buying in far more fertiliser and processed animal feed than they need, leaving a surplus of phosphorus in the soil and waterways.
The eastern and western Cleddau rivers in Pembrokeshire flow through farmland that produces as much as 25% of Wales' milk, and hundreds of dairy farms are now working out their “nutrient footprint” as part of what is believed to be one of the largest projects of its kind in the world.
The Eastern and Western Cleddau rivers unite to form the Daugleddau estuary and the harbour of Milford Haven Waterway
Why is the Cleddau catchment under pressure?
The Cleddau is seen as an extreme case because of the intensity of dairy farming in the area and the pressure that places on the rivers. Ric Cooper of The Cleddau Project, a local volunteer group working to restore the rivers, said the area has one of the highest densities of dairy cows in the country.
“The Cleddau is quite an extreme case,” said Ric Cooper, of The Cleddau Project, a group of local volunteers working to restore the rivers, which are designated special areas of conservation (SACs).
“We have one of the highest densities of dairy cows in the country [here] - it's a very successful and important industry for Pembrokeshire... [but] we also have a river that's not coping.”
Campaigners from The Cleddau Project, alongside the Welsh government's West Wales Nutrient Management Board, commissioned the study to better understand the problem and identify practical ways to reduce pollution.
In recent years the Cleddau rivers have been branded Wales' poorest performing protected waterways by Natural Resources Wales (NRW), the environment watchdog. They suffer from elevated nutrient levels that can cause algae to grow, reducing oxygen available to fish and other aquatic life.
The situation has become so serious that it has recently led to limits on house building, while campaigners have warned of “ecological disaster”.
Algal blooms are caused by excess nutrients in the water
Phosphorus, which is found in fertiliser and processed livestock feed, is considered one of the substances of most concern. While sewage discharges, misconnected drains and industrial run-off are also factors, the new Welsh government-funded research says agriculture is the primary driver of phosphorus pollution in the Cleddau rivers.
What did the researchers find?
Researchers from Lancaster University's RePhoKUs team examined how much phosphorus was brought into the area and how much left again in milk, cheese and other products. They found that far more phosphorus was coming into the catchment than was being removed through food production.
“The conclusion was that far more phosphorus was coming into the catchment than was being removed through food production.”
Local farms were generating a combined annual surplus of about 360 tonnes of phosphorus, the equivalent weight of 26 double decker buses. That phosphorus is left behind in the land and can continue polluting waterways for decades.
Dairy farms in Pembrokeshire produce as much as 25% of Wales' milk
Professor Paul Withers, who led the research, said there was in theory no need for farms to be buying so much artificial fertiliser, because there is enough phosphorus in animal manures across the county to meet crop requirements.
That means farms could potentially reduce expensive bought-in fertiliser by spreading cows’ slurry and manure more effectively, saving the county’s farmers an estimated £1.08m a year.
Researchers looked at how much phosphorus was imported into the county in the form of animal feed and fertiliser, and how much left in products such as milk
How are farmers being asked to respond?
Dairy co-operative First Milk, which has a large cheese-processing plant in Haverfordwest, Pembrokeshire, is trying to address the situation with all 700 of its farmers across the UK, including 200 in west Wales. The group has recently calculated the nutrient footprint of each farm by closely scrutinising the use of bought-in feed and fertiliser.
This data is being used alongside new maps, produced with the help of satellite imagery, which show the risk of causing river pollution on a field-by-field basis. Farmers will be expected to adjust where they spread fertiliser and slurry accordingly and introduce other mitigation measures to improve soil health and protect rivers.
They will also have to report annually on their progress.
“It's obviously looking to protect watercourses and reduce run off from the fields, but it's also trying to prevent excess nutrients being brought on farm,” said area manager Sarah Bennett.
“It's a missing metric for responsible farming,” added Lee Truelove, First Milk's director of regenerative farming.
Among those taking part is dairy farmer Tom Jones from Kilgetty, who said he wanted to make sure it was “the best environment” for his 250 cows “and for everyone else around”.
“We want to make sure it's the best environment for our cows and for everyone else around,” says farmer Tom Jones
“Whatever we buy onto farm we want it to stay on the farm, we don't want it leaving in the watercourses,” he said.
“I want to show that we're on the right side and we're trying as much as we can.”
Farmers involved in the First Milk trial are being given advice on how to mitigate the risk of polluting watercourses on their land.
Farms are also under pressure to act on nutrient pollution because several major supermarkets have signed up to the UK Food and Drink Pact, promising to source 50% of fresh food from areas with sustainable water management by 2030.
“We've had 20 years of really focusing on the carbon cycle and the carbon footprint is now a critical key performance indicator in every area of business,” Truelove explained.
“But farming also has a massive nutrient cycle and when that's out of balance obviously the watercourses are one of the consequences.”
First Milk has produces maps showing the risk of polluting rivers on a field-by-field basis for its farmers
Is this model unique?
Ric Cooper said he did not know of anything similar anywhere in the world, where 700 farms have had a farmgate nutrient footprint and are discussing with every farmer what can be done about it.
“I don't know of anything like that anywhere in the world where 700 farms have had a farmgate nutrient footprint and they're discussing with every farmer what they can do about it,” said Cooper.
The Cleddau study’s findings are being presented at an event at the Royal Welsh Agricultural Show in Llanelwedd, Powys on Wednesday, with those involved meeting Senedd members and MPs on the showground.
Cooper said the issue goes far beyond Pembrokeshire and reflects a wider nutrient imbalance across many areas of intensive livestock agriculture in the UK. He warned that without action, rivers will not recover to good health.
“This may be about the Cleddau but it's much wider than that,” Cooper added.
“We have nutrient imbalance across a lot of areas of intensive livestock agriculture [in the UK] and if we don't do anything about it then our rivers will never recover to good health”.
Mid and South Pembrokeshire MP Henry Tufnell, who sits on parliament's Environment, Food and Rural Affairs committee, said there was “a real opportunity on a national basis” to help farmers cut input costs and protect the environment — “a win-win”.
The study found farmers did not necessarily need to be buying-in artificial fertiliser and nutrients in their livestock's manure should be sufficient for growing crops
What has the Welsh government said?
The Welsh government welcomed the report and said “improving the health of the Cleddau requires action across all sectors”. It said the government-backed Cleddau nutrient management plan was already helping improve understanding of phosphorus and nitrogen pressures, identify priority interventions and support the long-term recovery of the rivers and the downstream marine environment.
“improving the health of the Cleddau requires action across all sectors”
A spokesperson added that the plan is already “helping to improve understanding of both phosphorus and nitrogen pressures, identify priority interventions, and support the long-term recovery of these important rivers and the downstream marine environment”.
