17 May 1996

A little planning can keep you in good odour

MUCK-SPREADING smells are a constant source of countryside friction. But a bit of planning using one of the Ministry of Agricultures codes of good practice should help to cut public criticism.

Almost half of all smell complaints about agricultural activities concern those from muck spreading, according to ADAS pollution adviser Alan Brewer. But there are ways of minimising potential problems, he stresses.

"As warmer weather approaches more people venture into the countryside. Even relaxing in the garden is a welcome break from winter melancholy, and, of course, windows are often left wide open in the summer.

"In these situations farmers will not want to cause annoyance to neighbours from slurry and manure spreading."

Smells travel

A key point is to recognise that smells can be detected a long way from the field, depending on the weather, type of slurry or manure and the method of spreading.

"Use a weather forecast to help choose suitable conditions," advises Mr Brewer. "These are sunny, windy days followed by cloudy, windy nights which cause maximum dilution with clean air. "Check the wind direction in relation to nearby housing before spreading. Avoid working in fields close to and upwind of houses, especially at weekends, bank holidays and evenings unless slurry is band spread or injected.

"It is worth remembering that smells from pig slurry, and cattle slurry or dirty water contaminated with silage effluent tend to be more objectionable.

"With conventional splash-plate slurry tankers, the odour concentration can be up to 15 times greater while spreading than immediately afterwards. During the following 12 hours, with slurry lying on the surface, there may sufficient odour release to cause problems," he warns.

"Reducing application rates to no more than 50cu metres a hectare of diluted slurry will allow it to soak into the soil and minimise the risks. On bare land the soil should be lightly cultivated or ploughed to mix in manures as soon as possible.

Reduce drift

"Smell drift can be reduced by using spreading equipment which gives a low, flat trajectory and large droplets to minimise slurry atomisation. Band spreaders which use trailing pipes to distribute dilute slurry provide further improvement," suggests Mr Brewer.

"Lastly, do not undo all the good work by overfilling slurry tankers and spreaders and spilling manure or slurry on the roads. It is also a good idea to clean the outside of spreading machinery regularly."

More information can be found in MAFFs Code of Good Agricultural Practice for the Protection of Air (PB0618), free from MAFF Publications, London SE99 7TP, (0645 556000). &#42

&#8226 Remember smell travels.

&#8226 Use weather forecasts.

&#8226 Check wind direction.

&#8226 Avoid working at weekends, holidays and in evenings.

&#8226 Restrict application rates.

&#8226 Cultivate bare land post-treatment.

&#8226 Avoid overfilling and road spills.