Last week, officials from the Department of Agriculture confirmed that many farmers in a nitrates derogation will likely see a reduction in the upper limit for stocking rates in 2024.

At the moment, farmers in a derogation can stock the farm up to a maximum of 250kg of organic nitrogen per hectare, but this is set to fall to 220kg organic nitrogen per hectare from 2024.

All livestock have a figure for organic nitrogen excretion. The total number of animals and their nitrogen excretion rates, divided by the number of hectares being farmed, gives the average organic nitrogen rate per hectare.

If this figure is above 170kg N/ha, farmers must either apply for a derogation, increase the amount of land farmed, decrease stock numbers or export slurry to a farm that is less than 170kg organic N/ha.

Last year, there were 6,809 farmers in a nitrates derogation, with over half of these in Cork, Tipperary and Kilkenny alone.

As outlined in Figure 1, the majority of derogation farmers are dairy farmers in Munster and south Leinster, where highly productive grassland farms are able to support stocking rates in excess of 170kg N/ha. Derogation farmers are permitted to stock their farms higher, subject to complying with a range of environmental measures that ordinary farmers are not subject to, such as nutrient management plans, soil sampling and a higher chance of inspections.

Two changes are happening at once; banding is being introduced, which assigns a different organic nitrogen figure per cow based on milk yield and the upper limit is set to reduce for most farmers.

Banding is set to increase the nitrogen excretion rates for dairy cows on 76% of dairy farms, from 89kg N/cow to either 92kg for herds producing between 4,500kg and 6,500kg of milk or 106kg for herds producing more than 6,500kg per cow per year.

Some 24% of dairy farmers whose herds produce less than 4,500kg of milk per cow per year will see their nitrogen excretion rates drop from 89kg to 80kg per cow.

Milk yield per cow will be calculated on a three-year average, so for next year it will be based on total milk produced (in kilos) divided by average dairy cow numbers in each of the years 2020, 2021 and 2022.

Nitrogen excretion rates

As most farmers will see an increase in their per-cow nitrogen excretion rates of between 3% and 19% and presuming no change is made to cow numbers or land area, their average nitrogen excretion rate will increase by either 3% or 19%. This means that for a farm stocked at 2.5 cows/ha (one cow/acre) and in the middle band for milk yield, organic nitrogen will go from 223kg N/ha to 230kg N/ha and for the same farm with higher-yielding cows in the top band, organic nitrogen will go to 265kg N/ha.

The higher-producing farm will exceed the derogation limit of 250kg N/ha next year. Both farms will be exceeding the new derogation limit of 220kg N/ha in 2024 if the farm is located in a catchment where nitrogen pollution is a problem.

Last year, the Environmental Protection Agency (EPA) published a document outlining which river catchments have excess nitrogen and where nitrogen loads need to be controlled.

As outlined in Figure 2, these catchments cover large swathes of the east and south of the country including the Maigue/Deel, Bandon, Lee, Blackwater, Suir, Nore, Barrow, Slaney and the Boyne river catchments.

The condition set by the European Commission in granting Ireland’s derogation is that in areas where water quality trends worsen or pollution or risk of pollution from nitrates is present, that the upper end of the derogation for organic nitrogen be cut from 250kg/ha to 220kg/ha at the 2023 midterm review.

The Irish Farmers Journal understands that four criteria will be used to assess water quality in the mid-term review next year. Of these, three criteria are likely to show improvement and will be OK, but the fourth criteria for assessment, eutrophication in estuary waters will be above the EU maximum permissible concentration and therefore the cuts will be introduced in these catchments.

According to the Department of Agriculture, approximately 50% of farmers in a derogation are stocked greater than 210kg organic N/ha.

Given that 75% of farmers will have a higher nitrogen rate after banding is introduced, we can expect that the number of farmers with an organic nitrogen rate greater than 220kg N/ha could be as high as 5,000 or 6,000 farmers.There are only two real options for these farmers by 2024 – get extra land or reduce stock numbers.

Rules around exporting slurry have already been tightened, meaning farmers who export slurry to remain compliant will need to export twice the volume of slurry to export the same amount of organic nitrogen off the holding. With more farms pushing towards 170kg N/ha, the number of farms able to take in slurry will also decrease.

Case study

According to Teagasc, based on historic data, 11% of dairy farmers will be in the top band for nitrogen excretion at 106kg N/cow/year from next year on. This is likely to have a massive impact on these farms and even more so if they are located in regions where the derogation is going to be reduced.

For those producing slightly above 6,500kg per cow, it would make economic sense to reduce this to be less than 6,500kg per cow.

Genetics and feeding rates will play a part here, but so too could manipulating cull cow numbers.

For example, take a farmer with 40ha and a herd of 100 milking cows producing an average of 6,700kg of milk per cow per year.

Under the new rules, the farm will have an organic nitrogen rate of 265kg N/ha. This farmer would either need an extra 2.5ha or else reduce cow numbers by six cows in order to remain below 250kg N/ha. To remain below 220kg N/ha, they would need an extra eight hectares or to reduce cow numbers by 17 cows.

However, if this farmer kept the same 100 milking cows and produced the same milk per cow, but managed to keep an extra four dry cull cows for the year it would mean that the average milk yield per cow would drop to 6,442kg per cow, placing the herd in the middle band at 92kg per cow.

Total nitrogen excretion rates would be 239kg N/ha and no additional land or no reduction in milking cow numbers would be required to comply with a 250kg/ha derogation, but the farm would need to be able to feed and house four cull cows for the year.

At an upper limit of 220kg N/ha, this farm would require an extra 3.5ha or to reduce overall cow numbers by eight cows.

The above scenario demonstrates the importance of being strategic around making sure farms at the margins are at the right lower side of the bands.

It also demonstrates why more bands are better than less bands.

The combined impact of banding and the reduction in stocking rate limits will be very serious for hundreds, if not thousands of family farms.

The fact that the derogation could be reduced for certain catchments was never discussed at the consultation stage, or indeed when the minister announced the granting of the derogation in March is shameful and renders the whole process a sham. Indeed, farmers will only know for certain what is happening in their catchment in September 2023, four months before the rules are enforced.

What is there to say that the 220kg limit won’t be lowered again at the next review in 2025? Will there even be a derogation at all the next time? This possibility was hinted at by senior Department officials last week. What is mind-boggling is that in over 14 years of the Agricultural Catchments Programme, which is funded by the Department of Agriculture and run by Teagasc scientists, no link has been found between stocking rate at farm level and nitrate losses on a catchment basis. That is a fact. I accept the total nitrogen load in a catchment does need to reduce, but that can be achieved by managing nitrogen inputs. This is something that the Department have failed to do up to now, with the fertiliser register only coming into play next year – 20 years too late for water quality.

If the Government is serious about improving water quality, it can be achieved without taking a knife to the derogation. However, a reduction in cow numbers as a result of cuts to the derogation is a convenient means of achieving emission targets.