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Boggy bulrushes to BioPuff® – re-wetting phase complete!

Aerial view of the bulrush wetter farming trail site - November 2023

The first stage of our exciting bulrush wetter farming trial, to re-wet the peat, is complete. Find out what we’ve been doing, why and what’s next.

Back in July 2023 we announced exciting new plans for a field scale wetter farming trial of typha, commonly known as bulrushes, on an area of drained agricultural peatland in Greater Manchester. The trial would re-wet the land to help reduce the damaging greenhouse gas emissions being released from the drained and oxidised peat, and then grow a commercial crop of bulrushes, a plant which thrives in these wetter conditions. The fluffy seed heads of the bulrushes would then be used to create BioPuff® – a revolutionary eco-textile that could replace goose down or polyester in puffer jackets.

Read: Are bulrushes the answer to sustainable clothing and farming?

We are pleased to announce that the first stage of the work, to re-wet the peat, is now complete. The drainage ditches that ran around the perimeter of the field have been blocked and a series of bunds (waterproof barriers of compressed peat) have been installed to stop water from draining off the field and allow the peat to return to its naturally boggy state.

Bunds have also been used to divide the field into a series of compartments where the bulrushes will be grown, and this also helps to control the water levels across the field keeping them at, or just below ground level throughout the year, which is just right for the bulrush crop.

Drone footage showing the completed first stage of re-wetting works at the bulrush wetter farming trial - November 2023

The drone footage shows that each of the growing compartments is now holding water, which will allow the peat to thoroughly re-wet. There are also a number of small water retention areas at the lowest end of the field which will be used to provide irrigation water during drier periods – standing approximately 1.5m deep, these filled up naturally in less than 24 hours!

Next steps

Winter 2023-24 will see the irrigation and internal water control pipes installed and the standing water will be allowed to settle and thoroughly re-wet the peat. Then in spring 2024 the bulrush seeds will be planted. Working with wetter ground means that we are looking at some exciting novel methods for planting, one option currently being considered is using specially adapted drones which fly low over the field scattering the seeds in their wake.

Find out exactly how we will be re-wetting the field, ready for planting the bulrush crop.

How does wetter farming affect surrounding fields?

Understandably, one of the most common questions we get asked about wetter farming projects is how will it affect surrounding fields? Will it flood them? The answer so far has been no. The installation of bunds means that any water that is on the wetter field stays there. As you can see from the drone footage, the wetter farming trial is noticeably wet, whereas the neighbouring fields are continuing with business as usual.

Although it is worth noting that even on the surrounding drained fields there are still numerous areas of standing water, showing how difficult many areas of lowland agricultural peat are becoming to farm conventionally.

It is also probable that under some circumstances neighbouring land will actually benefit from areas that have been converted to wetter farming. As water is being held on the wetter land this means that it isn’t draining into shared perimeter ditches, which can often become overwhelmed during periods of high rainfall, thus helping to protect these drained areas from flooding.

A person crumbling white fluffy bulrush seeds in their hands

Fluffy bulrush seeds - credit Saltyco®

What about methane emissions?

Another question we are often asked when re-wetting peatlands is about the effect of raised methane emissions from areas of peat under standing water. Methane is a very powerful greenhouse gas, more than 28 times as potent as carbon dioxide at trapping heat in the atmosphere, and areas of standing water on peatlands can be methane emitters.

There are a number of factors to consider here. Firstly, over winter and before planting, which is when the field will have the highest levels of standing water, microbial levels are naturally lowest, meaning that methane emissions (which result from any microbial activity in the peat) will inherently be reduced.

Also looking at methane measurements from our Winmarleigh carbon farm project and analysed by Manchester Metropolitan University, we have found these to be negligible - an average of only 17.8 grams per hectare per year over the first two years of the project. However, the peat depth at that site was only 1.5m, whereas as at the bulrush trial the peat is approximately 5m deep, so there is the possibility that methane emissions could be affected by the greater mass of organic matter. We also have to consider that the water levels at the carbon farm were generally kept just below ground level, so the increased water table required for bulrushes could also have an effect.

In partnership with Liverpool John Moores University, methane emissions will be measured from the bulrush trial water retention areas on a monthly basis starting in January 2024. This will allow us to understand methane levels and allow us to investigate potential mitigation measures.

It is also worth noting that whilst the water looks deep across the trial site, it is only actually a couple of centimetres above ground level.

 

We will continue to provide updates about how the bulrush wetter farming trial is progressing, but if you would like to find out more about what wetter farming is and why we are looking into it check out the video below.

Find out more about the what's, why's and how's of wetter farming

The trial has been made possible thanks to funding from the Paludiculture Exploration Fund, administered by Natural England and Defra, and is a partnership project between The Wildlife Trust for Lancashire, Manchester & North Merseyside, Ponda, Peel L&P and farmer, Steve Denneny.

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