Protect our water quality, spread slurry while the weather is fine
A Northern Ireland View: The recent good weather offers a great opportunity to make best use of the valuable nutrients contained in slurry and to maximise storage capacity for the coming winter.
Maximising grass growth is particularly important this year as fodder stocks are low on many farms. Every opportunity for producing and conserving fodder needs to be taken during the current growing season.
Perennial ryegrass swards have a growth peak in May and a second lower peak in July/August. It is especially important this year to make the most of this second growth peak by applying optimal rates of nutrients as slurry and fertiliser, in order to maximise forage production. Care should be taken to avoid ‘burning’ grass particularly during very hot, sunny weather. Band spreaders, trailing shoes or injection systems can help minimise this and maximise the uptake of nutrients.
Spreading later in the year will significantly reduce the yield response to any slurry applied, and conditions are likely to be less favourable with a higher risk of pollution to waterways.
Ideally, storing slurry over winter for application in spring would achieve the highest level of efficiency. However, having sufficient storage capacity is essential to allow for this and ensuring tanks are empty before stock are housed must be the starting point.
Following this advice will not only reduce your farm costs but will also help in protecting the water quality in our rivers and lakes as required by the Nitrates Directive. The actions required to avoid pollution are set out in the Nitrates Action Programme and some of these requirements are listed below.
- Keep your distance from waterways and do not spread within 20m of a lake and 50m of a borehole, spring or well, 15m of exposed cavernous or karstified limestone features, or 10m of a watercourse
- The distance from a waterway may be reduced to 3m where slope is less than 10 per cent towards the waterway and where organic manures are spread by band spreaders, trailing shoe, trailing hose or soil injection or where adjoining area is less than 1 ha in size or not more than 50m in width.
- Don’t apply more than 50m3/ha (4500 gal/ac) or 50 tonnes/ha (20 t/ac) of organic manures may be applied at one time.
- Use inverted splashplate, bandspreader, trailing shoe, trailing hose or soil injection spreading systems – not sludgigators.
- Allow at least three weeks between slurry applications.
- Don’t spread if heavy rain is forecast in the next 48 hours.
- Prevent entry of fertilisers to waters and ensure application is accurate, uniform and not in a location or manner likely to cause entry to waters.
- Remember that the closed period for spreading commences at midnight on 15 October.
By Jayne Mooney, Countryside Management Adviser, Department of Agriculture and Rural Development, Northern Ireland