The export of slurry from highly stocked farms affected by the lowering of the Nitrates Derogation figure appears to a focus of the government.

There is a 70% grant now available under the Targeted Agricultural Modernisation Scheme (TAMS) grant aid for slurry storage facilities, regardless of the sector.

This grant is available to all farmers who have a contract in place to import slurry.

The decision on Nitrates Derogation, which was confirmed by the European Commission last month, means that some areas of the country will see the derogation reduced from 250kg of organic nitrogen (N) per hectare to 220kg N/ha.

The EU’s Nitrates Directive permits the use of a maximum 170kg N, but the directive allows for a time-limited derogation from these rules in certain circumstances.

Under the regulations of the decision by the commission last year to renew Ireland’s derogation, the current derogation is due to expire on January 1, 2026, and the limit is due to reduce to 220kg N/ha on January 1, 2024 in certain areas, because the latest water quality results have not shown sufficient improvement.

The Department of Agriculture, Food and the Marine (DAFM) has confirmed that all farmers who have a contract in place to import slurry from other producers could avail of the TAMS grant.

But the issue with exporting slurry off farm remains, with farmers exporting slurry still doing so with a nitrogen (N) value of 2.4kg/m3.

Derogation

Exporting slurry however, really is the best solution for farmers affected by the lowering of the maximum stocking rate for derogation farms from 250kg of organic N to 220kg.

The biggest issue with the export of slurry is value given for a cubic metre of slurry which is only 2.4kg of N.

As already highlighted by Agriland, the biggest issue with exporting slurry is the fact that the N content of the slurry has been reduced from 5kg/t to 2.4kg/t by the DAFM under nitrates regulations.

This ultimately means that, compared to just a couple of years ago, you need to export twice as much slurry to meet the same reduction in organic N.

Taking an example of a farm of 50ha that is stocked at 245kg of organic N/ha, this farm from next January, would then be exceeding the legal limit by 25kg/ha or 1,250kg of N over the whole farm.

The conversion rate is that 1t equates to 1m3 or 1,000L of slurry, meaning this farm would need to export 521t of slurry (521,000L) of slurry to get below the new maximum stocking rate of 220kg of N.

A dairy cow produces 0.33m3/week according to DAFM. Basing this off a 18-week storage requirement, this means that one cow would produce 5.94m3.

For this farm to meet the reduction to 220kg by exporting slurry, it would be the same as exporting slurry from 88 cows.

An example such as this raises the question as to whether this is a viable option for many farms, and if other options also need to be looked at.

The farm exporting the slurry is also losing all the nutrient value contained within the slurry, which could impact the farm long-term.

Testing slurry

In the Netherlands, slurry is tested to determine the nutrient value when it is exported.

With the average N value of this slurry being 4kg/t, the reduction in the N value in Ireland was partly due to research which highlighted that fact that nutrient value of slurry was being decreased by water entering into tanks.

But there was, and continues to be, great variation from tank to tank and farm to farm, meaning that the value of 2.4kg and 5kg were both likely wrong.

For the export of slurry to work on farms that are affected by the changes in the derogation, some form of testing is needed to ensure that only the optimal amount of slurry is exported off farm.

Using the sample figures above, but changing the N value to 5kg/t would mean that the amount of slurry required to be exported would drop to 250t or 250,000L of slurry.

If the figure for N value was 4kg it would be 312.5t or 312,500L of slurry.

This is still quite significant amount of slurry, but more than half of what it would have to be currently.

This has the potential to cause more issues, but simply basing it off current figures is not going to work for many.

Some form of testing is going to be needed to ensure that the correct levels of slurry are being exported off farm and not excessive amounts.

Unlike other countries like the Netherlands, Irish dairy cows spend up to 300 days on grass – which means for around 260-300 days, little to no slurry is being produced on farms.

Cows are excreting dung directly onto fields, so compared to our European counterparts, we are producing much less slurry.

This ultimately means that the slurry we are producing is needed on farms to maintain and correct soil nutrient levels.

Sending this slurry off farm for the tillage sector to use, could lead to issues with soil fertility on farms.

Something does need to be done to allow dairy farmers to maintain cows numbers, but simply putting all the eggs in the exporting slurry basket seems misguided.

Other options need to be looked at also, such as contract rearing of young stock or leasing/renting of out blocks.