Farmers and conservationists are pioneering ways to reduce the environmental impact of peat farming as pressure mounts to reduce emissions from UK peatlands.
There are also calls for specific funding targeting peatlands to help farmers transition to more sustainable systems.
Lowland agricultural crops and grassland peatlands that have been drained, plowed and fertilized are responsible for more than half of the 23 million tonnes of annual carbon dioxide emissions from UK peatlands, analysis led by estimates from the UK Center for Ecology and Hydrology (UKCEH).
Jack Clough, of the Sustainability Research Institute at the University of East London, said that where carbon-rich peatlands have been drained, microbes convert peat to carbon dioxide in the presence of oxygen, “literally turning peat into thin air.
” The peat is disappearing at a rate of about 1-3cm per year and where the groundwater level is well below the surface — usually around 40-100cm — because of drainage, it produces about 25-40 tons of carbon dioxide per hectare per year, he said.
Soil scientist turned farmer Stephen Briggs, who farms on peat and clay in Cambridgeshire in the productive fens of East Anglia, said:
“The only way to completely stop peat degradation, lose these peat soils and completely reduce carbon emissions, is to stop farming and flood them.” Briggs acknowledged that this would have serious consequences for livelihoods, the economy and food security:
“There will always be trade-offs, trying to find ways to farm and manage the land that minimize further oxidation and degradation of peatlands as much as possible.” while still productive”.
While the internal drainage board monitors local groundwater levels, Briggs, who is a member of the Nature Friendly Farming Network (NFFN) and a member of the Environment Department’s Lowland Agricultural Peat Task Force (Defra), is taking steps to prevent and protect water loss.
His organic agroforestry system has rows of fruit trees with wildlife-friendly plants running through the fields, interspersed with conventional crops such as barley, wheat and vegetables.
The trees act like hedges to slow down wind and evaporation; avoiding artificial pesticides and fertilizers improves soil structure, and “companion” crops such as clover grown among the main crops keep carbon circulating through the soil, he said.
Soil health on his farm has improved; wildlife has increased; the fruit trees retain carbon and the land is more productive per acre, Briggs said.
He adds that a package of solutions is needed for peat farming: “There should be a separate innovation fund to let farmers try things on a small scale”, in addition to the new agricultural subsidy programme.
A few miles from Briggs’ farm, the Bedfordshire, Cambridgeshire and Northamptonshire (BCN) Wildlife Trust’s Water Works project is trying a more radical solution, which involves flooding the land while preserving productive agriculture.
The wet farming or paludiculture experiment, funded by the People’s Postcode Lottery, has created test beds where the water table is kept within 10cm of the surface to prevent carbon loss.
Crops, including bulrush, which can be used for insulation, and sweet manna grass — a gluten-free grain — as well as new crops, including wild celery, yellow flag iris and meadowsweet, with uses as food, medicine and gin flavors, were planted last year.
The crops all survived the very wet winter and dry April, although local Chinese water deer treated the flag iris as a salad bar, BCN Wildlife Trust’s Kate Carver said wryly.
Sphagnum moss, which has multiple potential uses, including as a substitute for peat in vegetable growing and gardening, will be planted this summer. Carver said:
“With our field trials and monitoring programs we want to prove that wet farming can prevent carbon loss; prevent the loss of peatlands; clean water and support wildlife.
” The plan aims to demonstrate that wet agricultural crops can be grown on a “true” peat farm and open up new opportunities for farmers, with the potential to ripple across the wider fens, she said.
Clough of the Sustainability Research Institute monitors along with colleagues measured carbon emissions, soil surface and groundwater levels at the Water Works scheme, he said research showed that any 10cm increase in groundwater levels could reduce emissions from peatlands by about three tons per hectare per year, although it had to rise to levels seen in paludiculture to largely stop them.
There is also evidence that some conventional crops can grow in soils with higher water levels, although more research is needed to assess the tradeoffs, such as lower yields, he said By raising the groundwater level of conventional agriculture, time can be gained to cultivate paludiculture (wet l peat farming) or develop other solutions such as “carbon farming” markets that pay farmers specifically to protect the carbon in their land.
“I think paludiculture can play a valuable role now, but in the short term some kind of environmental payment or subsidy will get it off the ground.
There is real potential for public and private funding to expand paludi culture, which will make a positive difference to the way we manage our peat,” he said.
A spokesperson for Defra said the Lowland Agricultural Peat Task Force was looking at how to better manage peatlands, both to reduce greenhouse gas emissions and to ensure continued profitable farming:
“The group is coordinating work already underway and examining new solutions, including innovative ways to control groundwater levels in peatlands.
” A separate report from Bangor University released last month advised that the UK must protect and restore its carbon-rich peatlands or risk undermining efforts to tackle its carbon emissions.
The study also concluded that not only on the nature-based solutions to climate change are effective, they can also help to increase biodiversity, improve human well-being and provide economic benefits.
In January 2020, the Climate Change Committee (CCC) noted that the UK government should urgently begin to make substantial efforts to change land use in the UK and change people’s diets to lower overall carbon emissions.
In its report, it included a section on the importance of restoring peatlands – at least 50 percent of the raised moors and 25 percent of the low moors.