£1m Water Works project in Cambridgeshire will help save our peatlands

Caroline Fitton, of the Wildlife Trust in Cambridgeshire, examines a scheme that could-have international implications for agriculture.

The government’s Nature Capital Committee has warned that cultivated peatlands such as the Fens, where high winds whip up and remove the dried-out surface soil in the phenomenon known as ‘Fen blow’, are losing about 1-2cm a year and emitting seven million tonnes of carbon dioxide. Ultimately the peat will be completely lost, hitting the productivity of the important arable land, unless action is taken.

A pioneering two-year scheme, the Water Works project, is being run by the Wildlife Trust in Cambridgeshire at the Great Fen and aims to tackle these problems in partnership with Cambridgeshire ACRE, the University of East London and the Centre for Ecology & Hydrology.

The project is exploring a new type of wet farming system using crops that like having soggy feet, and could help protect soils and cut carbon emissions: wetland crops such as bulrushes for biomass and home insulation boards, wild grain for food and wetland moss to replace peat in gardening will all be trialled.

Raising the water table to grow the crops will help prevent the peat soils blowing away, reduce the carbon dioxide emissions from soil drying out and store it instead, and offer many benefits for wildlife. It also aims to provide farmers with economically viable crops – including innovative new products.

Awarded £1million by the People’s Postcode Lottery Dream Fund earlier in the year, the project is now under way.

Kate Carver, Great Fen project manager, says: “We are trying to create a more sustainable system for farmers through developing crops that grow in wetlands systems, crops that like their feet wet, which will protect the peat soils, and reduce carbon dioxide emissions. We are hoping we can prove these wetland crops can grow in the Fens and demonstrate they are economically viable for farmers, and help farmers protect their natural assets such as soil.”

If the system could be proved to work, it would be adopted by neighbouring farms in the area and could eventually lead to changes in agriculture on any peat area in the UK - and the world.

Crops being tested include bulrush whose tubers can used for animal fodder and stems can make building materials and cavity wall insulation when dried out, while sphagnum moss can be used to replace peat as a growing medium.

The seeds of Glyceria fluitans, also known as floating sweet-grass or water manna grass can be used to make porridge or milled for bread, and could have a high value as a niche cereal. Novel crops with edible or medicinal properties that will be trialled are likely to include meadowsweet, with ambitions for a meadowsweet-flavoured gin, yellow flag iris and wild celery.

Technology will be used to measure the carbon emissions from the trials: equipment known as carbon flux chambers will be used to measure the carbon dioxide and methane with different crops and environmental conditions to find ones which can help store carbon.

Dr Ross Morrison, flux scientist at the Centre for Ecology and Hydrology, explains: “We will use a flux chamber approach to continuously measure CO2 and methane fluxes. We will use these data to quantify the carbon balance of the different crops (whether they function as net sinks or sources for atmospheric carbon), and will compare these values to those of conventional drainage based agriculture.

“We will also analyse response of carbon fluxes to environmental controls (eg water levels, soil moisture, temperature, light, etc), with the goal of developing or improving existing models of these crops, that could then be used for assessments of land use change."

Wildlife Trust AGM to be held on October 12, 2019

Calling all members: the Trust’s AGM or Members' Day is on Saturday 12 October at the Clay Farm Centre, Trumpington, Cambridge, starting at 9.30am talks from a range of speakers including this year’s guest, Prof Rebecca Kilner, Professor of Evolutionary Biology at the Cambridge University Department of Zoology. Her research has the potential to play a key role in addressing conservation problems by predicting, for example, species’ capacity to adapt to a changing world. It's a wonderful opportunity to ask about the latest work that the Trust are doing for local wildlife, and to meet staff, volunteers, trustees and, of course, fellow members. Plus there’s the chance to explore Trumpington Meadows reserve in the afternoon in the expert company of people who know the site well.

Visit wildlifebcn.org/agm2019.

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