Energy crop in trials to restore flood plain soils

Miscanthus growing in flood water
Miscanthus growing in flood water

Farmers looking for a crop to grow on flood-prone land, and help improve soils after flooding, as well as provide fuel for biomass, may soon have the answer. This is thanks to some new trials to examine how the energy crop, miscanthus, survives in water-logged land and its effect on the soil after flooding.

The trials are being jointly-run by the Institute of Biological, Environmental and Rural Sciences at Aberystwyth University, and miscanthus supply chain specialists, Terravesta. They come some 18 months after the floods which devastated in the Somerset Levels and are being funded by the Engineering and Physical Sciences Research Council (EPSRC).

“We know miscanthus has the ability to tolerate flooding when it’s mature, but there’s a gap in the data about its tolerance during its establishment stage, and this is during the first two years of growth,” says Dr Sarah Purdy, plant physiologist, from Aberystwyth University.

“What’s really exciting about these trials is that we’re also going to analyse the health of the soil, following the floods, when compared to other land-uses,” says Dr Purdy.

The trials will see the biomass crop, miscanthus, grown on commercial flood-prone sites, on plot-scale sites and in controlled environments under glass, to monitor how the crop copes with prolonged flooding, particularly in its establishment stage, and analyse the structure and nutritional health of the soil.

“We believe miscanthus may be beneficial to soil because this perennial crop has a life cycle lasting up to twenty years, in which time the soil experiences no tillage, just an annual harvest. Therefore the soil can maintain its structure which promotes colonisation by beneficial microbes and creatures such as earthworms.

“Miscanthus has a large under-ground rhizome which recycles nitrogen and other essential nutrients from the stems before harvest so that no fertilizer needs to be applied to achieve high yields,” explains Dr Purdy.

“The implications for farmers struggling to grow crops on waterlogged land, are vast. If the nutrient recycling benefits offered by miscanthus can still promote healthy growth after a flood event, growers could reduce expenditure on rehabilitating land through fertilizer application by growing this crop.

The trials will also be able to establish whether the crop has multiple uses, such as increasing soil stability, restoring water-damaged soils and mopping up nutrients on the edges of waterways,” says Dr Purdy.

Miscanthus supply chain specialists, Terravesta, is a partner in this project, and will provide land farmed by its southern region manager, Mike Cooper, on the Somerset Levels.

Mike Cooper, who manages the rhizome supply to other growers, and grows the crop himself, supplying Terravesta, for biomass pelleting, says: “We’ve believed for a long time that miscanthus improves the quality of soil, and we know it thrives on problem, flood-prone land. We need to plan for the future, especially on the Somerset levels, where growers are looking at planting alternative crops,” says Mike.