Britain’s lowland peat is one of nature’s best carbon stores. It is also the country’s most productive farmland – 40 per cent of the UK’s fresh vegetables come from this rich, black soil, which we’ve been draining for centuries and, in the process, unwittingly releasing vast amounts of climate-warming gases. So much so that these areas account for 3 per cent of the country’s total emissions; this is a serious issue.
The greenhouse gases belched out from this land alone is greater than all the schools in Britain, more than the construction industry, and nearly as much as the whole of the National Health Service.
Pick up a pack of shop-bought peas… the label says British-grown, it might even say organic; but what it doesn’t tell you is that these peas, planted in lowland peat, could potentially have a carbon footprint that is ten times larger than soya beans grown in the Brazilian Amazon.
It’s no wonder that the UK government says current farm practices on drained peatlands are inherently unsustainable. It’s not just to do with emissions – the peat itself is disappearing at up to 3cm per year. It’s an issue that many farmers, researchers and policy makers are now trying to tackle since peat restoration is only happening at a fifth of the rate that is needed.
Rewetting 243,000 hectares of England’s total expanse of lowland peatland would help with the UK’s Net Zero ambitions, since submerged soil stops vast amounts of carbon dioxide and methane escaping. It would also allow biodiversity to thrive and reduce soil erosion. But such a move could also reduce food security, lead to more imports or push up the price of vegetables. This comes at a time when families need more healthier food in their diets, not less. Peat presents a complex problem.
“The general public aren’t really aware of the implications of this issue, however, farmers are. Over time we are going have to change our ways. Yet there are no easy answers. We’re losing peat rapidly, so we need to do something fast. Some farms are at risk of losing all their peat within the next 20 years and they’re really worried, so there is drive for change,” explains Dr Jenny Rhymes from the UK Centre for Ecology & Hydrology (UKCEH).
It’s a complex challenge
Unsustainable use of peat is often in the news and there’s now a proposed UK ban on the sale of horticultural peat in retail outlets. A new bill will be put forward to Parliament in January, which aims to speed this ban up, with no new sales mandated by the end of 2025. In a bid to move towards more sustainable horticulture, many retailers have already stopped selling it (the RHS, for example, stopped selling peat-based compost in 2019, and have said that all plants sold in their outlets and shows will be peat-free by 2026).
At the same time, Riverford is having a lot of success developing its own peat free media for growing vegetable seedlings. And Co-Op – through its Carbon Innovation Fund – is now financing food production projects that don’t damage peat. Such commitments show that the issue is gaining momentum, with a major supermarket chain selling peat-free mushrooms. Could we expect the same for veg over time? Not unless the public wants to pay more for their produce.
“The reality is, lowland peat areas are where the UK is a cost effective producer of vegetables; luckily it is only a third of the area under cultivation. If I were trying to tackle this problem head on I would start by ditching the arable crops grown on peat,” states Dustin Benton, managing director of Forefront Advisors and former policy advisor at the Green Alliance.
Intensive grassland or growing cereals on lowland peat that is then used for livestock feed and bioenergy, is also of concern. These crops could easily be grown on mineral soils. The numbers are sobering – biomethane from maize grown on peat soils emits three times more carbon dioxide than if you just burned natural gas from fossil fuels – and these areas of corn have been expanding in the last decade.
Time for paludiculture
Protecting lowland peat areas by deploying paludiculture could be a gamechanger. This involves raising the water table in the peat soil, which can reduce emissions by ensuring the carbon in the soil is not exposed to oxidation, since water can occupy over 50 per cent of the spongey peat by volume.
During the summer, lowland peat soils used for vegetable production are often drained to more than 90cm below the surface. Even raising the water table depth by as little as ten centimetres can reduce emissions by three tonnes of CO2 equivalent per hectare, per year. And some vegetables such as celery, lettuce, leeks and brassicas don’t mind a higher water table (of up to 40 cm) since their roots aren’t deep.
Such projects as the UKCEH’s Lowland Peat 3 and Wildlife Trust’s wet farming projects are now investing heavily in paludiculture. But, this type of agriculture is still in its infancy. While trials on farms are helping researchers understand the best way to grow crops with higher water tables, there’s yet little commercial roll out at scale – perhaps rewetting peat isn’t gaining enough impetus, investment or attention it really deserves.
“If you look at the amount of money that still that goes into tree planting, it gets far more funding than peat research. Most people know that planting a hectare of trees reduces emissions, but I don’t think that many people are aware that rewetting one hectare of peat soils would produce even better results,” says Zoe Lipkens, PhD researcher at the University of Leicester.
The Climate Change Committee has set ambitious targets for rewetting and restoring peat by 2050. Recommending full restoration of 25% of the UK’s lowland peat areas and rewetting 50% of lowland grassland as part of the country’s Net Zero strategy – to date, however, this goal is not on track.
Raising the water table in veg-filled fields is not as easy as turning on a tap. The fens have been drained for centuries – the historical mindset, along with past government diktats, has been to keep the water out. The deep, high carbon-emitting, peat is also not uniform, covering multiple levels, fields and farms.
At the same time, a complex network of watercourses and Internal Drainage Boards manage the water levels. Their aim is also to protect urban areas from flooding. It means that individual farmers don’t always have the ability to rewet fields at will or the right incentives to do so.
“We need to work out a business model for farmers that allows them to make more money from peatland restoration, whether that’s raising the water table to limit carbon emissions, or whether it’s fully rewetting and ending up with a business model that’s focused on restoring biodiversity, making enough money off the future carbon saved and the nature preserved,” states Benton.
Give the credit to farmers
Incentives for lowland peat restoration are now available through the Countryside Stewardship and the new Environmental Land Management (ELM) scheme, but these are flat rate fees. They don’t reflect the true price of what could be achieved by farms who rewetted fields and locked in specific volumes of carbon. Fully rewetting on a typical lowland peat farm and paying the farmer to avoid emissions would raise their incomes from £200,000 per year to over £800,000 a year, according to the Green Alliance.
Until we realise the importance of peat as a carbon store, and prioritise the means to pay for it, the status quo will prevail because growing crops in the fens on top grade, peat-rich, land is a lucrative business, employing 80,000 people and generating more than £3 billion for the economy. Vegetables in this area alone raise £357 million in annual revenue.
“Raising water tables to levels that are close to the ground surface (between 10 to 30 cm) is likely to limit the types of crops you can grow, but there are some crops that tolerate these conditions. If you raise the water table on peat you can get a payment from the government of £1,400 a hectare per year, but this doesn’t compete with revenues made from high value crops like lettuces,” details Dr Rhymes.
She continues: “There’s also scope to implement wetter management that doesn’t stop farmers from cropping as usual, particularly in areas that are over-drained. This is totally unnecessary, we can raise the water table on these soils to slow the rate at which the peat is lost to decomposition, preserve our soils for the future, reduce emissions and still produce vegetables.”
In the future, it is only better financial incentives for lowland peat growers in areas such as the East Anglian fens that will motivate them to change their ways en-masse. For instance, where carbon credits go direct to farmers.
A proper land-use framework from government could also help shift certain crops including winter vegetables, potatoes, cereals and sugar beet onto mineral soils. The ultimate aim will be to create a mosaic of landscapes with multiple benefits collectively delivering food security, climate mitigation and biodiversity. These goals are proposed in the latest WWF report.
Then there are those who know the land best of all. “I think that farmers in these areas should be brought together to come up with their own ways of solving the problem. What do they think is practically possible?” concludes Rhymes.
I think you are talking about 2 different issues when talking about the ban on peat growing media and soil erosion in the same breath. Growubv media doesn’t use uk peat. Extraction ended years ago. Growing media is for plants growing in containers while soil erosion is caused by cultivation of soil for growing veg. But loss of top soil is not exclusive to peaty soils, it is a worldwide problem for all cultivated soils. Without top soil we have no crops so carbon emissions is lrovay threat of our problems. But please peat in growing media has nothing to do with this. It is a separate issue