With 85,000 tiny green celery plants glistening brightly against dark, peaty soil, the field in Lancashire looks as unremarkable as any other.
But this crop is a pioneering “wetter farming” trial that could demonstrate how degraded peatlands can be restored to capture carbon and boost biodiversity while providing a livelihood for farmers.
Rindle Field, a 5.4 acre former potato patch in Greater Manchester, has been bought by Lancashire Wildlife Trust, which is running the first British trial of paludiculture, or wetter farming, using traditional, commercial crops.
By growing celery in wetter-than-usual conditions – with the water table allowed to rise up to between 10cm and 50cm below the surface of the soil, rather than drained away – the peat soil can store much more carbon, and not dry out and emit carbon as occurs on peat-rich arable land across the country.
Peatlands make up 12% of Britain’s land area and store huge quantities of carbon when in good condition. However, only one-fifth of Britain’s peat is in a “natural” condition: the vast majority is drained for farming or forestry, grazed by livestock, dug for horticulture or burned. Greenhouse gas emissions from degraded peatlands are make up an estimated 4% of Britain’s total annual emissions.
In Lancashire, Manchester and North Merseyside, 98% of lowland peatland has been destroyed, releasing vast quantities of carbon into the atmosphere.
If peatlands are restored to bog, emissions can be rapidly reduced: research conducted by Manchester Metropolitan University at Winmarleigh “carbon farm” – also owned by Lancashire Wildlife Trust – has shown an 86% reduction in greenhouse gas emissions from an area of re-wetted peatland in just one year compared with a drained area converted to grazing pasture.
But farmers may not be able to afford to restore productive peaty soils to bog or want to reduce food production, and so the Wildlife Trust is testing whether wetter farming could be an emissions-reducing compromise in some areas.
“We’re pragmatic and we think it’s unrealistic to expect farmers to take land out of food production and restore it to bog,” said Sarah Johnson, project manager of the Lancashire Wildlife Trust’s Lancashire Peatland Initiative. “We also have to think about the livelihoods of people who live and work in this area as well. Are there other ways to manage agricultural peat soils which are better for biodiversity and better for the climate with soils in a condition where they can store and sequester carbon as well?”
The Wildlife Trust employed the grandson of the farmer who first drained Rindle Field to block field drains and drainage ditches.
“He didn’t dare tell his grandad what he was doing,” said Mike Longden, senior project officer for Lancashire Peatlands Initiative. “But it’s an indication of how farming is changing.”
Researchers from Liverpool John Moores University will measure greenhouse gas emissions from the trial site.
Scientists calculate that by halving the typical water table depth below deep peat cropland from 1m below the surface wetter farming could reduce UK-wide carbon emissions from degraded peatlands by 3.3m tonnes each year – nearly 1% of total emissions – with a negligible increase in methane emissions.
“If we could see a significant reduction combined with a profitable crop then this could really be an exciting way forward for the management of lowland peatlands for both people and our planet,” said Longden.
The celery trial is using conventional farm machinery, to reassure farmers that expensive specialist equipment is not required. One concern among farmers about wetter farming is how to stop it flooding every field. To create the trial field, the Wildlife Trust installed bunds, low walls of compressed peat which form a watertight barrier, to enable the water table to be raised without flooding adjacent fields.
“We want to use farmers’ knowledge and experience,” said Longden. “It’s a LWT-led project but we’re also working with one of the local farmers to prep the land and he will carry on farming it and their input has been really valuable.”
Although the Wildlife Trust are farming conventionally with herbicides to ensure there are not too many variables to confound the scientific assessment, they are already seeing biodiversity benefits on the celery field, with irrigation channels – filled only by rainfall – home to five dragonfly species.
The rewetted field is also helping keep water on Rindle Moss, 16.5 acres of degraded peatland which is now a Lancashire Wildlife Trust nature reserve. Rewetting this fragment of bog could attract the rare large heath butterfly with other species already present including the black darter dragonfly, lapwing, hobby, brown hare and short-eared owl.
“Protecting that biodiversity is really crucial for what we as a Wildlife Trust want to do,” said Longden. “We’re trying to showcase how farming and biodiversity can actually live together – by managing a high water table that will protect key flora and fauna of the remnant bog as well and create some really nice natural connectivity as well.”
As well as celery, the three-year trial will test other wet-loving crops such as cranberry and typha, or bullrush, which can provide fodder for livestock, environmentally friendly insulation and biofuel.
If the first celery crop is successful in six months’ time, it presents a conundrum: what will the Wildlife Trust do with 85,000 celery plants?
The charity plans to donate some to community food banks and, with the help of a competition for the best celery recipes, fill its nature reserve cafes with celery soups and salads.
