What is the impact of 'banding' on my farm?

Changes to the nitrates regulations will restrict cow numbers on many dairy farms this year, with a decision on further restrictions for derogation farms next year being made in September. Edward Burgess, Agricultural Catchments Programme Specialist, discusses further.

Since the start of this year, the nitrogen (N) excretion rate from dairy cows is based on the herd's average milk yield. This is called 'banding'. Last year, every dairy cow in the country was assigned a figure of 89kg N per head.  This year, the N excretion rate per cow will be either 80, 92 or 106 kg N depending on your herd's average milk yield.  For a farm moving into the high band, this results in a 16% increase in N, which could bring them over the 170kg/ha or 250kg/ha N (derogation) limit. 

Many farmers move organic manure off farm to bring their organic N back under the regulatory limit. There are two other changes to the nitrates regulations this year that make this option more difficult. 

• The N content of a cubic meter of slurry has changed from 5 to 2.4kg. This change was made because analysis over the years has shown that most cattle slurry stored on farms has a nitrogen content close to 2.4 kg per m³. The result of this change is that double the volume of slurry has to be moved to achieve the same reduction in N;
• Tillage fields and grassland on farms stocked above 130kg N/ha are assumed to have high phosphorous levels unless an in date (<4 years old) soil analysis shows otherwise. Therefore, farms and fields without soil samples will not be able to receive manure from another farm.

The impact of these changes was checked out on farms in Teagasc’s Agricultural Catchments Programme as a case study, and it showed up some interesting results.

• Moving into the high band (106 kg N/cow) did not necessarily result in exceeding the farm stocking rate limit.
• Farms already (pre-banding) moving organic manure to comply with stocking rate regulations are being driven further over the limits, and the change in N content in slurry is having a larger impact than herds moving into the high milk yield band.
• While some regions of the country are impacted more than others, the implications on a farm scale are individual.

To be able to deal with these new regulations it is important that each dairy farmer knows how they will be impacted, if at all.  Just because your neighbour has to make big changes it doesn’t mean you have to, or vice versa.  To help plan your own farm's situation, Teagasc has put together an Excel banding calculator.  Farmers in ICBF’s HerdPlus can copy and paste herd details from the Nitrates Stock Report and enter details from the co-op performance report and the farm area.  The workbook calculates changes required in (a) cow number, (b) area farmed or (c) slurry exports to meet three stocking rate limits, 170, 220 or 250 kg N/ha.

You may well ask where this 220 kg N/ha limit is coming from. At the start of this article, I mentioned that a decision on further restriction for derogation farms next year being made in September. The European Commission decision last April to approve the derogation contained a requirement for a review of water quality to take place in 2023. The Nitrates Directive is all about water quality after all. The derogation decision states that where water quality is not considered satisfactory, the maximum stocking rate on farms located on land draining into these locations will be limited to 220 kg N/ha. Indications from the EPA’s water reporting currently indicate that river catchments along the south and east of the country will not meet the standards required to maintain the 250kg N/ha derogation limit. While the final decision on this will not be made before September, it would be prudent to do your own calculations now to see if this is of relevance to your own farm. In many cases, this will not be a big deal one way or the other, but for some it will be very significant and being aware now of how it plays out on your own farm is vital.

Access the Excel banding calculator here.