Wet farming on the Great Fen

This post includes an interview with Richard Lindsay and Jack Clough, researchers based at the University of East London’s Sustainability Research Institute.

Over the past four hundred years or so the wetlands of East Anglia have been gradually but thoroughly drained and dried out, and today 99% of the original fen area has been converted to agricultural use.  

What was not anticipated at the start of this process was that it would have unwelcome side effects. While the peaty soil of the fens proved very rich and fertile, for instance, draining it caused the land to sink. 

As the historical geographer Henry Clifford Darby wrote in 1940: “Neither Vermuyden nor any of the other drainage engineers foresaw, when they planned and executed their schemes, that as soon as they started to drain the area, the surface of the peat-fen would become rapidly lower. This lowering was due in part to the shrinkage of the peat as it dried, but it was due also to the wasting away of the drying peat surface owing to bacterial action.”

As a result, the rivers, cuts and man-made canals intended to drain the land were soon higher than the land itself and so the drainers had to build hundreds of windmills, and then steam engines with scoop wheels, and subsequently diesel and electric pumps, in order to lift the water into the drainage channels before it could drain away and discharge into the sea at the Wash.

While our understanding of the science and physics of draining peatland has developed over time, and the drainers have (bar occasional disastrous events and periods of financial downturn) managed to keep the Fens dry, the challenges of doing so have grown rather than diminished. 

What Darby does not say in the quote above, for instance, is that when peat is dried it also becomes susceptible to wind action. This can create disruptive “Fen Blows” where the topsoil literally flies away in high winds. In the process, valuable soil is lost, and drivers are confronted with drastically reduced visibility on nearby roads, with all the dangers inherent in that.

But the most worrying long-term consequence of draining the fens might seem to be the role it has played in climate change. Drying and digging out peat causes a disproportionate release of carbon dioxide (CO2), the most significant long-lived greenhouse gas in Earth’s atmosphere. 

As explained in the interview below, “peat soils drained for agriculture release around 25 tonnes of CO2 per hectare per year.” 

Historically, peat was widely used as a fuel source as well, and today it is still dug out for, amongst other things, use on farms in other parts of the country, for market gardens and for sale in garden centres. 

The science here is clear: as a greenhouse gas carbon dioxide absorbs and radiates heat. As this site explains, human activity (e.g. the burning of fossil fuels, deforestation and the destruction of peatland) has increased greenhouse gases to the point where they have tipped the Earth’s energy budget out of balance, trapping additional heat and raising Earth’s average temperature. 

It is now generally accepted that this is the cause of the extreme rain and flooding we are now experiencing, and is responsible for a worrying rise in seal levels, one that poses a great threat to the stability of the planet. It is estimated that by the end of the century global mean sea level will have risen at least one foot (0.3 meters) above 2000 levels, even if greenhouse gas emissions follow a relatively low pathway in coming decades.

Photo credit Richard Lindsay/Jack Clough

In retrospect, we might wonder whether draining the Fens has come at too high a price. Either way, it seems unlikely that they can be maintained in a dry state in the future.

Reducing emissions

The harsh fact is that climate change poses an existential threat for mankind. This, say scientists, means that it is vital we stop releasing CO2 into the atmosphere. And this in turn, they say, means we have to end our reliance on fossil fuels, and put a stop to the massive deforestation still taking place around the planet – activities that are releasing ever larger amounts of CO2 into the atmosphere.

One immediate challenge is that some of the energy intensive activities that release large amounts of CO2 cannot be easily or quickly decarbonised (e.g., aviation and manufacturing). Reducing emissions in these industries currently is said to be either too expensive, technologically too complex, or simply not possible. This includes the steel and cement industries, industries that will be essential for building the infrastructure that a zero-carbon economy will require.

Rather than setting a gross-zero target, which would reduce emissions from all sources uniformly to zero, therefore, governments are setting net-zero emissions targets. This is viewed as a more realistic approach since it allows for residual emissions to continue – as this site explains.

As such, residual emissions from those sectors most difficult to decarbonise can be offset by removing emissions from the atmosphere – to create “negative emissions”.

In other words, in conjunction with reducing emissions we can remove CO2 that has already been released into the atmosphere – sequestering it by means of carbon sinks. The aim is to achieve an overall balance between emissions produced and emissions removed. This is what is meant by ‘net zero’.

As this site puts it, doing so will allow the impact of any source of residual emissions that cannot be avoided to be nevertheless eliminated “by permanently removing an equivalent amount of atmospheric carbon dioxide.” 

Bath taps

One way of thinking about this is to analogise the situation with a bath that has its taps turned on. A balance needs to be achieved by either turning the taps down (reducing emissions) or draining an equal amount down the plug (removing emissions from the atmosphere.)

As noted, negative emissions can be attained through the use of carbon sinks that trap and sequester CO2 – using either nature or engineered solutions. Most straightforwardly, this can be done by planting more trees, which absorb the CO2 in the atmosphere by means of photosynthesis (essentially, trees consume CO2). This can be done through afforestation (planting new forests) or reforestation. 

Photo credit Cunningchrisw CC BY-SA 4.0

But while planting more trees reduces CO2 in the atmosphere this strategy is not always effective, as this site (and this one) explain. Moreover, while trees clearly have an important role to play in sequestering CO2, they cannot reverse climate change on their own.

For their part geoengineering techniques like Direct Air Capture (DAC) remain uncertain solutions and tend still to be controversial.

The good news is that peat is a very effective way of sequestering carbon. In fact, it is said to be the planet’s most efficient natural carbon sink. As the Ramsar web site argues, peatlands “cover only about 3% of earth’s land surface, yet they hold twice as much carbon as all of the world’s forests combined.” For a sense of how much carbon dioxide peat can sequester see this visualisation.

Interestingly, the UK is said to contain 13% of the world’s peatlands. This includes fenland as well as raised bog  and blanket bog.

The point here is that while drying or burning peat releases a disproportionate amount of CO2, if it is rewet and restored it can potentially remove a disproportionate amount of carbon dioxide from the atmosphere.

In other words, significantly reducing our use of peat and restoring peatland could, in effect, provide a double benefit – i.e., reduce the levels of CO2 being released into the atmosphere while sequestering a lot of carbon that has already been released.

In addition, peatland can (counterintuitively) help prevent flooding. By storing water produced during heavy rainfall it can slow the water’s flow to areas vulnerable to flooding and reduce the occurrence of flash floods. The waterlogged condition of peatland also reduces the incidence and spread of wildfire.

Peatlands also support a wide variety of flora and fauna and so can contribute to biodiversity. True, the number of plants and animals that depend on blanket bogs is more limited, but many birds currently struggling to survive rely on them.

In September, for instance, it was announced that – for the first time in decades –  curlews and golden plovers (both of which are near-threatened species) have been breeding on an area of restored blanket bog in Snowdonia. This has been achieved by blocking old drainage ditches and deep gullies in the peat and creating mini dams. As a result, pools have been able to form and the landscape has become boggy again.

We could note that approximately 30% of  the peat bog in Wales is found within the boundaries of Snowdonia National Park.

In light of the positive roles that peatland can play it is no surprise that we are seeing growing calls to preserve, protect and restore it. 

Paludiculture

Photo credit WTBCN

The challenge when it comes to the Fens of East Anglia, however, is that the drained peatland is now viewed as a food production powerhouse worth £3.1bn to the local economy. For that reason it is now referred to as the “Breadbasket of Britain”.

At the same time, the region’s population is growing rapidly, with the number of households in the East of England expected to rise 27% by 2033, from 2.5 million to 3 million. This suggests we can expect land to be in increasingly short supply, with demand coming both from farmers and from house builders.

How realistic is it, therefore, to think that we can restore the Fens to their historical watery state? After all, we are not talking about a mountainous national park like Snowdonia dedicated to hill farming, forestry and tourism. While the Fens may be sinking they are still viewed as excellent farmland. Unsurprisingly, therefore, farmers tend to be more focused on maintaining and strengthening current drainage systems than on blocking drains and ditches to enable wetland to reform.

Nevertheless, rewilding and rewetting agricultural land is precisely what the Great Fen project is working on. Launched in 2001, this is now one of the largest restoration projects in the country. The plan is to connect Woodwalton Fen, Holme Fen and other nature reserves to create a larger site. And thanks to lottery money and other grants it has been acquiring agricultural land and taking it out of production – a strategy farmers view with some suspicion and scepticism.

But what if Fenland farmers could have their cake and eat it? What if it were possible to rewet and restore peatland and yet still be able to use it for agricultural purposes? This is another part of the Great Fen vision.

Along with the Wildlife Trust of Bedfordshire, Cambridgeshire and Northamptonshire (WTBCN), Cambridgeshire ACRE, the University of East London  (UEL) and other partners, the Great Fen has embarked on a project called Water Works – a pioneering initiative to study new wet-farming methods that could allow the peat in the Cambridgeshire Fens to be restored. The hope is that in doing so it will be possible to develop new ways of using the fens productively while mitigating the effects of climate change and enhancing biodiversity.

In short, Great Fen is experimenting with a novel land management technique (known more formally as paludiculture) that it hopes will allow commercially interesting crops to be cultivated on wet or rewet peatlands under conditions that maintain the peat body, facilitate peat accumulation, and sustain the ecosystem characteristic of natural peatlands.

Water Works is attracting both attention and money: in July, for instance, the National Lottery Heritage Fund announced that it was granting the Great Fen another £8 million to develop the project. Some of this money will also be used to purchase more land.

Great Fen will share with others any lessons learned about wet farming along the way. Importantly, it is also working with a number of local farmers, food producers and landowners. The hope is that these groups can be persuaded to embrace the new farming techniques.

As the University of East London’s Richard Lindsay and Jack Clough explain in the interview below: “[W]e hope to show that agriculturalised peat soils can be used more sustainably in terms of carbon while providing new crops, products and markets”.

The aim, they add, is to “create a win-win situation where the land can remain productive and gain significant ecosystem service benefits compared to conventional drainage-based agriculture.”

It is important to bear in mind here that current drainage-based farming methods release a lot of CO2 into the atmosphere and so are significant contributors to climate change. In addition, the food manufacturing processes that they feed into depend on the use of CO2 – as the recent shortage of the gas in the UK has made clear.

There are, however, some important questions to be answered before Water Works can claim to offer a way forward. Will the new methods being developed be able to prevent the peatland continuing to sink for instance? Will they be able to maintain the necessary water level that healthy peatland requires? And, vitally, will they enable the peat to start growing again.

In the hope of being able to answer these questions in the positive Jack Clough has installed monitoring equipment in the wet farming zone.

Surface level marker. Photo credit Lindsay/Clough

Eyes on the Bog

Called “Eyes on the Bog” (EoB), the monitoring system being deployed is designed to provide a low tech, scientifically robust and repeatable way of monitoring peatland over the long-term. (For details of how EoB monitoring equipment is installed see this blog post).

Interestingly, EOB also allows citizen scientists to take part, which could encourge local communities to become involved.

If Water Works can demonstrate that wet farming offers a practical carbon neutral alternative to today’s drainage-based farming methods, if it can win over farmers, and if it can engage the public in a positive way, it can hope to make a positive contribution to mitigating climate change, while improving biodiversity at the same time.

Either way, the takeaway point is surely that, whatever happens, people living in the Fens are going to have to learn again to live in a watery landscape. The combination of climate change, a landscape that continues to sink in its dry state, and a coastline now experiencing continuous erosion as it too sinks, means that those living in East Anglia are going to have to adapt sooner or later, one way or another. The key questions are whether this can be done in a managed way, and in a way that will allow the land to provide the kind of value that today’s drainage-based agriculture does.

As Francis Pryor put it to me when I interviewed him earlier this year, “Even if by some miracle we do manage to control and reduce climate change, I think it will be inevitable that areas of the Fens will flood. The trick will be to manage it.” 

Interview with Richard Lindsay and Jack Clough

Q: Can you start by saying something about yourselves and the research you do at the University of East London?

A: We work in the Sustainability Research Institute at the University of East London. We are involved in several peatland projects across the UK. These range from monitoring peatland restoration project successes in Wales, investigating the potential for peatland greenhouse gas reductions in the Peak District, through to developing paludiculture systems and products in East Anglia. 

Photo credit Jack Clough

Q: You are currently taking part in the Water Works project, which is based at the Great Fen in Cambridgeshire and is a partnership between several different organisations and institutions in addition to the University of East London. As I understand it, the project was launched in 2019 and was made possible by a £1 million award from the People’s Postcode Lottery. Can you say something about the project, its aims and objectives, and its timescale?

A: The Water Works project was launched through the innovative ‘Dream Fund’ which was funded through the Peoples Postcode Lottery. This allowed us to secure an initial 2 years’ funding to set up our ‘Wet farming’ trial site here in East Anglia.

This was truly a dream opportunity to connect knowledgeable and enthusiastic partners and achieve the UK’s largest paludiculture site. The project aims to showcase a ‘shop window’ of wetland crops that can be cultivated at scale, whilst also developing a Fen UNESCO Biosphere reserve.

Photo credit Richard Lindsay

By achieving these aims we hope to show that agriculturalised peat soils can be used more sustainably in terms of carbon while providing new crops, products and markets. Finally, the project has been extended for an additional year with funding from DEFRA, which will allow us to catch up on Covid-19 related delays. [See also news that in July the National Lottery Heritage Fund provided another £8 million for the project].

Key area to tackle

Q: The goal then is both to enable more sustainable farming and to avoid further depletion of the peat soil characteristic of the Fens by rewetting it and farming in a wet landscape. I think the point is that unless peat is kept wet it blows away and/or degrades. Rewetting will also help trap carbon and so reduce carbon emissions which, in turn, presumably will help mitigate climate change. What are the challenges in turning drained agricultural land into wetland able to grow new crops?

A: Absolutely, we know that peat soils drained for agriculture release around 25 tonnes of CO2 per hectare per year. This is obviously a key area to tackle to reduce the climate impact of farming on peat soils and help achieve net zero by 2050.

These carbon emissions also result in a hidden consequence – soil subsidence. Subsidence will result in the loss of 1 – 3cm of peat soil per year, with some peat soils at less than a metre depth, it won’t take very long for these to be lost completely. 

Q: Another term for wet farming is paludiculture, which I think implies farming on peatland. The peat aspect apart, what is different and distinctive about paludiculture? Is it a better way of wet farming? Are the methods and benefits of paludiculture different to, say, those achieved by using rice paddies?

A: Paludiculture is the scientific term (based on the Latin Palus, which means swamp) for the more public friendly term ‘wet farming’. Both terms aim to achieve the same thing: i.e. the re-wetting of peat soils to reduce the loss of peat, while enabling the cultivation of wetland species as crops for new products and markets.

Paludiculture is focused on crop production so differs from conservation, although it provides similar benefits. By rewetting drained peat soils for paludiculture, we hope to create a win-win situation where the land can remain productive and gain significant ecosystem service benefits compared to conventional drainage-based agriculture.

The main Ecosystem benefits from paludiculture are greatly reduced carbon emissions, nutrient and water regulation, biodiversity provision and the provision of raw materials.

Rice paddies are a slightly different system, in that they are often constructed on mineral soils not peat soils. The standing water we associate with rice paddies is a means of reducing competition from weeds. Paludiculture typically aims for a high-water table, close to or at the peat surface, but not generally deep areas of standing water.

Planted up wet farming beds. Photo credit Henry Stanier

Q: What other benefits can we expect to see from rewetting peatlands – i.e., in terms of biodiversity? What are the downsides of doing it?

A: Studies have shown peatland rewetting for restoration purposes to be highly effective at increasing habitat provision for invertebrate and avian species. Typically, our peatland areas have been drained and degraded, reducing the habitat available for both peatland specialist and generalist species.

 Peatland re-wetting may cause pressures on land uses that rely on peatland drainage, for example areas of farmland or forestry. However, in terms of climate impact the re-wetting of peatlands has been shown to be a net benefit in terms of radiative forcing. And the sooner we re-wet the better. 

Trial crops

Q: As I understand it, this is an experimental exercise and Water Works is a pilot that might or might not prove successful. Is that right? What crops are being trialled and what uses do you anticipate them having? What other benefits do you expect introducing new agricultural crops will provide?

A: Yes, this is one of the UK’s paludiculture trial plots, we are building on the knowledge of paludiculture demonstration projects across Europe and North America, which are a few decades ahead of us in this area!

We are trialling a range of ‘main crops’ which we know have great potential and a history of commercial use – these include Common Reed (Phragmites australis) and Reed Mace (Typha latifolia), which can be used for building materials, insulation and even have a potential role in manufacturing Lithium batteries.

Reed and bullrush planting. Photo credit WTBCN

We are growing Bog moss (Sphagnum sp.) which has great potential to be used as a much more sustainable replacement for horticultural peat, as well as its medicinal properties. The addition of sweet manna grass (Glyceria fluitans), which has a history of human consumption, to our trials offers the potential to develop a wetland food crop of the future. 

We are also trialling a number of ‘novel’ crops at a smaller scale to provide a shop window for innovative applications. 

Conventional agriculture has had something like 9000 years of development, and we cultivate very few species of plants. By developing a wide range of potential wetland crops we are hoping to identify a wide range of uses and provide the opportunity for innovative product development. 

For example, we are working with a company aiming to turn the seeds of reed mace (Typha latifolia) into a truly sustainable fill for padded jackets. 

Reed Mace in paludi beds. Photo credit WTBCN

Well placed

Q: As I understand it, most peat in this country is in Scotland, Ireland, Wales, and the North of England. Is there a particular reason why Water Works is taking place in Cambridgeshire, rather than in one of those parts of the country? Are there similar schemes being undertaken/planned in other parts of the country?

A: The majority of peat in the UK is found in the uplands, in the form of what is termed ‘blanket peat’ because it blankets whole landscapes. Opportunities even for highly productive conventional farming in such upland areas are limited, and the same is true for paludiculture unless carbon stores and other ecosystem benefits begin to attract substantial finance.

Paludiculture is thus currently focused on lowland areas of peat, with the East Anglian Fens representing by far the largest area of former lowland peat. The waterworks project is thus well placed for these trials: 99% of the original fen area has been converted to agriculture although despite this, large amounts of peat remain.

Unfortunately, these drained areas release a volume of carbon disproportionate to their area.

Indeed, agricultural croplands and grasslands on lowland peat soils represent the largest net Greenhouse Gas (GHG) source from UK peatlands from all forms of land use, occupying around 15% of the total UK peatland area but contributing more than 50% of the total GHG emissions from UK peatlands. 

Photo credit Alistair Grant, bokeh photographic

Hindsight is only partly useful

Q: Looking back in hindsight, did we make a mistake when we drained the fens? Given that much of the Fens is below sea level, given that the coast in Eastern England is tilting downwards, and given that climate change is causing sea levels to rise, is it inevitable that the Fens will in any case at some point have to return to being a watery landscape?

A: Hindsight is only partly useful – at the time of drainage, climate change was not a recognised problem. The motivation was to convert land from ‘wasteland’ to ‘productive’ land for use by conventional agriculture.

Our modern understanding is very different – wetlands in their natural state are some of the most productive habitats in the world, and they are our most efficient terrestrial carbon store – holding more than twice the carbon of all the rainforests combined. The ecosystem services provided by our wetlands are maximised when they are in good condition, certainly a job made very difficult by historic and modern drainage.

In the long term, peatland drainage to maintain conventional agriculture is unsustainable. As long as drainage occurs, the land will subside (at a rate of 1 – 3cm per year) driven by the continued loss of the (finite) peat soil. This inevitably lowers the position of the land relative to sea level, which is further exacerbated by isostatic rebound as the land sinks (mm’s per year).

With sea levels predicted to rise, the status quo of drainage-based land management will become increasingly challenging.

Drainage requires infrastructure to move water from the land to the sea, which is costly – and the costs are rising as the land becomes ever lower. Eventually the cost of pumped drainage may become prohibitive.

Q: Thank you very much for taking the time to answer these questions. 

Photo credit Henry Stanier