The Department of Agriculture has said that a review of technical tables around the nutrient content of slurry and the slurry excretion rates of livestock is set to complete by December.
At present, dairy cows are required to have 0.33m3 of slurry storage per week of housing. Farmers are required to have sufficient storage for 16 to 22 weeks, depending on their location.
The corresponding figure in Northern Ireland is 0.37m3 of slurry storage per week, a 12% difference. In Britain, that figure varies between 0.294m3/week and 0.448m3/week depending on the milk yield per cow.
The Nitrates Expert Group, made up of officials from Teagasc, EPA and the Departments of Agriculture and Housing, has already proposed introducing bands for organic nitrogen excretion rates based on milk yield.
In Denmark, farmers are required to have 0.445m3 of slurry storage per cow per week, but organic nitrogen excretion rates are on a sliding scale based on actual milk yield.
Speaking at a Department of Agriculture webinar on the new proposals in the Nitrates Directive, Bernard Harris from the Nitrates Division said that the review of the tables is being carried out to assess if existing slurry storage capacity figures are considered to accurately reflect changes in animal size over the last number of years.
Jack Nolan, senior inspector with Department of Agriculture, moved to clarify the position on soiled water in the new nitrates proposals.
In response to a question about the requirement to separate soiled water from slurry he said: “Obviously, if someone has a large tank and there’s four weeks of storage for soiled water in it, plus the storage for slurry that can get them out over the 16 week period in this part of the country, that should be considered to be OK and that’s what you should submit [to the consultation process] if that’s what you believe.”
However, it should be pointed out that where soiled water and slurry mix, by the Department’s own guidelines that product is considered slurry.