Sweeping changes are proposed in the recently released consultation document on Ireland’s review of the nitrates directive.
As previously reported, the consultation document proposes changes to the closed period for slurry spreading, changes to stocking rates, reductions in chemical nitrogen allowances and major changes to how soiled water is managed.
The proposed changes are by far the most radical since the directive was introduced 16 years ago.
Eye of the storm
If unchanged by the consultation process and accepted by the EU, the majority of farmers in Ireland will be affected in one way or another, with dairy farmers in the eye of the storm.
The following scenarios highlight some of the issues individual farmers will be faced with.
A new measure is that soiled water must be collected and kept separate to slurry on all holdings. The spreading of soiled water is banned for a 60-day period between mid-November and mid-January starting next year. Furthermore, a minimum of four weeks of slurry storage is required by 31 December 2024. Therefore, on farms that produce soiled water over the winter, the minimum storage required for soiled water must be sufficient for 60 days.
Research carried out by the late Denis Minogue from Teagasc showed that, on average, dairy cows produced 25l of soiled water per day, excluding the contribution from rainfall. This includes water used for washing milking machines, parlours, collecting yards and the contribution of dung and urine from the cows.
The amount of soiled water produced on spring-calving farms decreased significantly during December and January to less than 10l/cow/day in line with the dry period.
On many dairy farms, there are no dedicated soiled water tanks.
Instead, soiled water is directed to slurry tanks. In such cases, new soiled water tanks will need to be constructed by the end of 2024.
What size these tanks need to be will be determined by herd size and farm system. A typical 100-cow, spring-calving farmer who stops milking for six weeks during the winter will require a minimum of four weeks’ storage for soiled water. At 25l/cow/day, this is a total requirement of 70m3.
At an estimated cost of €120/m3 for a concrete tank, the cost of this soiled water tank will be €8,400.
Where cows are milked through the winter as is now common on many spring-calving farms, a minimum of 60 days’ storage will be required.
In a 100-cow herd and based on an average of 25l/cow/day of soiled water being generated, a 150m3 tank will be required, costing in the region of €18,000 if construction costs are €120/m3.
A lot depends on the type of tank constructed and the cost of materials at the time of construction.
There has been a sharp rise in building costs over the last 18 months and true construction costs are largely unknown.
Another consideration is the cost of getting the soiled water into a new tank, either through channels or pumps. In cases where soiled water is currently mixing with slurry, more remedial action will be needed. This could include building a partition in the slurry tank to isolate soiled water and then pumping this to a new, dedicated soiled water tank or store.
The amount of organic nitrogen excreted per dairy cow is set to change in line with how much milk that cow produces.
For herds producing less than 4,500kg milk per year, the rate will be 80kgN/ha. For the majority of herds producing between 4,500kg and 6,500kg of milk, the rate will be 92kg/N/ha/year, which is up from the current figure of 89kg.
The biggest increase is for the 27% of herds producing in excess of 6,500kg of milk per year as these will now have a rate of 106kgN/ha, which is an increase of 17kg on the current level.
This means that higher-yielding herds will hit the stocking rate limits with fewer cows than lower-yielding herds.
For example, excluding youngstock, a 100ac farm in a nitrates derogation can be stocked with 125 low-yielding cows, 109 medium-yielding cows or 94 high-yielding cows.
A 100ac farm not in a derogation can be stocked with 85 low-yielding cows, 74 medium-yielding cows or 64 high-yielding cows.
There are two stocking rate ceilings that farmers need to be concerned about.
The first is the 170kg organic N/ha ceiling above which farmers must either export slurry or enter a nitrates derogation.
The other ceiling is 250kg organic N/ha above which farmers must either export slurry or they will be in breach of the derogation. High-yielding herds will hit these ceilings quicker under the new proposals.
The high-yielding demonstration herd at UCD, with an overall stocking rate of 2.4 cows/ha, will now be in breach of the 250kg organic N limit. In this case, extra land will have to be introduced or fewer cows milked or slurry exported in order to remain compliant.
The new nitrogen bands will apply from next year.
A 10% to 15% reduction in chemical nitrogen allowance is proposed. This will reduce the amount of chemical nitrogen allowed by between 25kgN/ha and 38kgN/ha. For farms with an overall stocking rate greater than 2.3 livestock units/acre, the new maximum amount of chemical nitrogen that can be applied will be between 212kgN/ha and 225kgN/ha. The lower rate is proposed for parts of the country where N loss rates are highest, including the catchments feeding into the Boyne, Slaney, Barrow, Nore, Suir, Blackwater, Lee and Bandon rivers.
The new limits, combined with stricter controls on fertiliser sales will present a serious feed deficit problem on farms that have been reliant on high levels of nitrogen fertiliser to grow enough grass.
Response to additional nitrogen above 200kg N/ha/year is typically around 16kg of grass per kilo of nitrogen applied. Therefore, a reduction of 25kg N/ha will result in a reduction of 400kg of grass per hectare and a reduction of 38kgN/ha will result in a reduction of 600kg of grass per hectare.
Across a 100ac farm, this means between 16t and 24t less feed will be grown where nitrogen is reduced by 25kg/ha and 38kg/ha, respectively.
If cow numbers are to remain static, this lost production will have to be replaced by introducing extra feed or taking on extra land. Otherwise, cow numbers will have to reduce, or other stock contract-reared in order to provide sufficient grass.
A phased increase in the closed period where slurry cannot be spread is proposed. Slurry must be spread by 30 September in 2022 and by 15 September in 2023 and subsequent years.
The opening date for slurry spreading remains unchanged. It’s important to clarify that these proposals do not necessarily mean that extra slurry storage is required on all farms.
It simply means that slurry tanks must be emptied by the above dates.
However, where animals are housed after the closed period, the slurry produced cannot be spread until the following spring.
This measure will severely affect farmers in Zone A who operate confinement or semi-confinement type systems feeding silage or zero grazing and beef farmers who finish cattle in sheds in autumn/winter.
They previously needed 16 weeks of storage but now require a minimum of 18 weeks of slurry storage.
Farmers in Zone C are already required to have 22 weeks of slurry storage while farmers in Zone B are already required to have 18 weeks of slurry storage.
There is talk that, in future reviews, the closed period for spreading chemical and organic fertilisers could be moved away from fixed dates and more towards weekly permits based on weather and grass growth predictions.