For our third blog post focusing on peatlands, NIAB's Head of Farming Systems Research Dr Elizabeth Stockdale explains what paludiculture is, discusses some potential crops for the UK and talks about some ongoing projects...
Paludiculture, or farming with high water tables, is a system of agriculture for the profitable production of wetland crops under conditions that support the competitive advantage of these crops.
In the context of lowland peat soils, it is most usually achieved through raising the water table to achieve wetland conditions. While the term ‘paludiculture’ is a recent one, its practice in England goes back generations.
The aim of paludiculture systems is to combine the harvest of wetland crops for food, fodder, fibre and fuel with the provision of vital ecosystem services. This differentiates paludiculture from conventional rice paddy systems where environmental management is an add-on rather than an integral part of the system design.
The term paludiculture was coined by researchers in Germany to provide a descriptive name that could be used across a range of productive systems that provide a sustainable alternative to drainage-based agriculture in peatlands. Paludi comes from the Latin palus meaning ‘swamp, morass’ and is linked to ‘cultura’ meaning growing or cultivation to highlight the active management of these systems to deliver multiple outcomes.
Peatlands used for paludiculture seek to maintain the average groundwater level in the growing season around 20 cm below the soil surface or higher, and the minimum groundwater level is never more than 40 cm below the soil surface. This creates peat preserving conditions, but unless there are significant organic material inputs, peat generation will not occur.
Paludiculture systems may also be used to strip nutrients from surface waters and reduce wind erosion. This concept provides production opportunities for the necessary, fundamental change in land use of drained peatlands to a more sustainable, wetter land use, which should benefit both the regional economy and the climate.
The Greifswald Mire Centre, in Germany, was established as a science-policy interface to support the restoration and sustainable management of peatlands and has pioneered the development of new paludiculture systems.
In Germany and The Netherlands there are pilot sites with harvestable sphagnum lawns, reed and typha (bullrush) plantations, where the crop biomass is harvested as fuel or to provide fibre for construction, as well as wet meadows with grass species adapted to a higher soil moisture content used as pastures, e.g. by light dairy cows or water buffaloes. The identification of crops for wet peatlands is essential for the implementation of paludiculture.
The Database of Potential Paludiculture Plants (DPPP) gives a global overview of conceivable paludiculture plants and their uses. Each ‘Plant Portrait’ collates information on plant characteristics and morphology, distribution and natural habitats, modes of cultivation and propagation and utilisation options.
To assess the paludiculture-potential of plants the DPPP defines four levels of suitability based on three criteria: preservation of peat soil, market potential and existing implementation. Preservation of peat soil is the primary concern of paludiculture. In parallel, the UK Paludiculture Live list contains 88 native species with promising potential for paludiculture in the UK. The greatest potential for paludiculture is currently in the areas of fibre and biomass crops for construction, energy and a range of bio industrial uses.
Examples of paludiculture crops that have potential for use in the UK grouped by products/markets
- Food: bilberry, celery, cheese, cranberry, meat, nettle, sedge grains, sweet grass grains, watercress and water pepper
- Herbal remedies, medicines and biomedical: bilberry, bog myrtle, cranberry, comfrey, hemp agrimony, lady’s smock, meadowsweet, round leaved sundew and Sphagnum moss
- Flavourings: bilberry, bog myrtle, meadowsweet, round leaved sundew, water mint and wild celery
- Construction materials: fibreboards – typha and reed, light weight aggregates – typha, and roofing (thatching) – reed
- Furniture and decorative homewares: alder, rush and willow
- Bioenergy: typha, reed and willow
- Growing media: Sphagnum moss
- Fabrics: typha seed heads (down replacement) and nettle
- Industrial chemicals: reed (silica) and Sphagnum moss.
Further research is needed to identify existing products that can be replaced by paludiculture crops, or processes where paludiculture crops could displace current feedstock and identify the scale of opportunity which may exist for paludiculture in these markets.
It is also important to understand the potential for UK paludiculture crop production to be displaced by imports once markets are established for these crops. More work is also needed to develop best practice agronomy and management guidance for paludiculture crops.
The Lowland Agricultural Peat Taskforce identified that paludiculture provides an effective way to farm and in the same field also reduce the current deterioration of drained lowland peat soils as part of the mosaic of integrated solutions and land-use change needed in lowland peatlands. Its roadmap to commercially viable paludiculture has now been adopted by UK Government.
The roadmap sets out a plan to make the widescale adoption of paludiculture a commercial reality over a 10-year timescale, starting from 2023, by developing the business cases for different crop and product combinations. By 2033, the aim is to have unlocked paludiculture as a new opportunity for some farmers, particularly those farming on marginal or low-lying land.
Current soil carbon trading schemes are not suitable for use on peat soils and the existing Peatland Code was designed for restoration projects. However, as paludiculture pilots are implemented at wider scale, with generation of the underlying data to quantify the benefits of paludiculture in terms of greenhouse gas emissions, farmers may also be enabled to access a second stream of funding via carbon trading schemes in addition to sale of paludiculture products.
Within the Nature for Climate Fund, Natural England is delivering the Paludiculture Exploration Fund (PEF) for England. The PEF has funded 12 projects (2023-2025) across England focused on tackling the barriers to developing commercially viable paludiculture on lowland peat soils.
NIAB is working with Natural England to deliver co-ordination and wider engagement across the PEF. The aim is to build, and then facilitate engagement amongst, a paludiculture community of interest and action for lowland England, drawing together the best of knowledge and experience from academia, farmers and wider supply chains including purchasers, processors and manufacturers. The Paludiculture Community can be found at paludiculture.org.uk.
More funding is also being made available to address key barriers to paludiculture such as the costs and practical challenges of water management for rewetting in lowland peat landscapes. These projects, together with existing work, such as the Great Fen National Lottery Heritage Fund Project Peatland Progress, will tackle barriers along the supply chain and address issues associated with a range of crops suitable for paludiculture.
Overall, these projects will support practical initiatives that will help in the reduction of peat wastage and greenhouse gas emissions and drive us along the road to a future where paludiculture is an integrated part of the UK landscape.
For more information on paludiculture, including events, projects and resources see paludiculture.org.uk.
This article originally appeared in the Autumn 2023 edition of NIAB’s Landmark magazine. Landmark features in-depth technical articles on all aspects of NIAB crop research, comment and advice. You can sign up for free and get Landmark delivered to your door or inbox: