Slurry seems to be the hardest word

A talk by Helen Browning, CEO of the Soil Association, on 2 November left me pondering the problems of farming and waste.  Helen is a compelling speaker and, despite battling the after-effects of a cold, tackled a lot of topics with energy and thoughtfulness.

Is big beautiful?

She explained why the Soil Association has opposed the development of a “mega pig farm” in Foston, Derbyshire. Despite the threat of libel action, they have successfully argued that airborne drug-resistant organisms released from such developments may harm human health – South Derbyshire District Council has now voted not to let the proposal go ahead.

But she readily admitted that in some respects mega farms may be no more of a threat to their local environment than smaller, traditional ones. Falling margins on a range of produce is driving farmers to scale up, without necessarily investing in the infrastructure and management practises to avoid pressurising the local environment.   Higher densities of livestock and the overuse of fertilisers are contaminating rivers with nutrients, bacteria and sediment. We all experience the cost of agriculture’s environmental damage, whether through contaminated bathing waters, harm to economic fish species like salmon and shellfish, or through our water bills, which reflect water companies’ obligation to remove these pollutants from drinking water.

Mega farms can at least finance proper waste infrastructure – and the planning concerns they raise mean that they’re likely to be scrutinised and required to do things properly. For smaller farms, storage for slurry and manures is a major up-front expense – and the long term saving on inorganic fertilisers just isn’t sufficient motivation. A Defra ministerial team heavy on Tory ex-farmers shows little sign of pressing for farmers to change.

Hard to digest

Helen also looked at how we recycle slurry into something useful. Anaerobic digestion (AD) is seen as an excellent solution for dealing with food waste, turning it into biogas for energy and digestate for fertiliser. Even so, care is needed as the nutrients in digestate are relatively bioavailable and can contribute to eutrophication of rivers and lakes unless properly applied.

But to deal with slurry. on-farm digesters (supported by Feed in Tariffs) need a “co-digestate”. Maize is the crop of choice – but associated with some of the worst soil erosion on UK farm land. Farmers are lobbying for a subsidy for maize grown for co-digestion. If they succeed, an important but covert policy change will have occurred turning AD from a waste disposal technology into an industry in its own right.

There are no easy solutions to these problems. However we deal with agricultural waste, it will require investment – and the option of doing nothing is perhaps the most costly of all. Society has grown used to cheap, plentiful meat without understanding its impacts. Supermarkets have grown used to cutting costs at the expense of sustainable supply chains. Government has grown used to getting CAP money “out the door quickly” instead of targeting it to help farmers provide clean food, water and air.

With a growing population, food security is high on the agenda and UK farming is set for “sustainable intensification”. But the jury is out on whether this will prove to be an oxymoron. A change of mindset that sees us eating smaller quantities of higher quality, less intensively farmed meat may be needed if agriculture is to play its proper, positive role in UK ecosystems.