Share this page:
Other services (opens in new window)
Sets a cookie

Advice system for farmers improves water quality through better manure recycling

28 November 2008

Researchers funded by the cross-Council Rural Economy and Land Use (RELU) programme and led by BBSRC-sponsored North Wyke Research scientists have developed an advice system to help farmers recycle manure safely and avoid polluting watercourses.

The team, which included researchers from the Universities of Exeter and Lancaster, have developed a model which farm advisors can use to help farmers understand the most efficient and cost effective ways to reduce the risk of manure contaminating watercourses. This has benefits for the farming industry, fisheries and tourism.

The interdisciplinary team of natural and social scientists assessed the risk of water contamination at 77 farms in the Taw river catchment in North Devon, taking into account factors such as grazing livestock and topography, and surveyed farmers to assess their knowledge about risk and find out how they managed manure on the farm.

They also monitored microbial water quality at fixed locations over several seasons.

The project has identified four factors that affect the level of risk:

  • Accumulated microbial burden to land (e.g. how manure is applied and deposited, stocking density)
  • Landscape transfer potential (e.g. the topography of the land, whether there are slopes, streams and so on)
  • Infrastructure (e.g. how the manure is stored, whether there is hard standing)
  • Social and economic obstacles (e.g. whether the farmer has had training about risk, whether he can afford to invest in infrastructure)

The team then constructed a model framework that shows the levels of risk in these four areas, expressed graphically as a "kite" shape. The colour shows the overall level of risk from green representing "low risk" to red representing "high risk". The shape demonstrates where risk is highest. This provides a useful tool for farm advisers working with farmers, as reducing the risk reduces the shape of the kite.

Dr Dave Chadwick from North Wyke Research who led the project explained: "The project covered a lot of areas, including public perception of the risks involved, so it was very wide-ranging.

"Our examination of microbial evidence threw up some unexpected results. We found that untreated sewage from the farmhouse was a significant factor in the total microbial load in quite a few cases, and how and when manure is applied also has an effect. Some practices may have unintended consequences.

"Injecting slurry, for example, does reduce ammonia emissions, which is the intention, but also favours survival of organisms.

"So how can an individual farmer reduce the risk of polluting watercourses? The kite model is designed to help. It shows whether the farm is high risk, and how the farmer can apply his efforts most effectively and at least cost. So we expect it to be a particularly useful tool for farm advisers."


Notes to editors

Link to original press release:

The Rural Economy and Land Use Programme is a multi-disciplinary collaboration between the Economic and Social Research Council (ESRC), the Biotechnology and Biological Sciences Research Council (BBSRC) and the Natural Environment Research Council (NERC), with additional funding provided by the Scottish Government and the Department for Environment, Food and Rural Affairs. See for more information about the RELU programme.

North Wyke Research is the home of grassland research within Rothamsted Research, a sponsored institute of BBSRC. The mission of North Wyke Research is to undertake internationally excellent science that elucidates the interactions between soil, microbes, plants, animals, water and the atmosphere within grassland-dominated landscapes.


Matt Goode, Head of External Relations

tel: 01793 413299

Tracey Jewitt, Media Officer

tel: 01793 414694
fax: 01793 413382