Slurry is a vital source of organic fertiliser on farms and if used correctly, it can significantly reduce the need for chemical fertilisers.
But over the coming weeks, farmers need to start putting plans in place to ensure that tanks are empty or close to empty once the closed period starts.
Slurry
Over the last week to ten days many farms have been able to harvest their second cut of silage.
This has been labelled by many as a smash and grab, due to the very small window of weather that has allowed farmers to harvest crops.
Once silage has been harvest it is important to get nutrients back on the fields and into the soils where silage crops were harvested.
Slurry is the easiest way to replace the phosphorus (P) and potassium (K) that has been removed.
On a farm where seven bales or 5,600kg/ac of fresh-weight silage were harvested, there is an offtake of about 70 units of nitrogen (N), 11.2 units of P, and 70 units of K.
On a typical dairy farm, about 3,500 gallons/ac are needed to replace the P and K that has been removed.
Due to the tender ground conditions, spreading slurry using a pipe system is probably going to be the best method to prevent damage.
But it is also important to ensure that conditions are suitable for slurry spreading and although the pipe system is beneficial it should not be used to put slurry onto land where there is the potential for runoff to occur.
Under the nitrates regulations, slurry must not be spread when:
- The land is waterlogged;
- The land is flooded or likely to flood;
- Heavy rain is forecast within 48 hours (regard to weather forecasts issued by Met Éireann);
- The ground slopes steeply and there is a risk of water pollution having regard to factors such as surface runoff pathways, the presence of land drains, the absence of hedgerows to mitigate surface flow, soil condition and ground cover.
Closed period
Farmers need to be aware that the closed period for slurry this year is from from October 1, 2023.
This is a week earlier than 2022 when the closed period started on October 8.
Over the last two years the start of closed period has moved forward 14 days, which means that slurry application plans on farms for the backend must also change.
On some farms, slurry would have been applied to paddocks during the final rotation, but on many it needs to now be applied during the second last rotation.
Dairy farms also have to storage for parlour washing for 21 days this year from December 10-31.
This will increase to 31 days in 2024.
This cannot be mixed with slurry and must be stored in a tank separate to slurry – if it is stored with slurry the storage period based on your zone applies.
Slurry safety
It is possible that this slurry has been undisturbed for a number of months so farmers should be on high alert by mixing and spreading.
It is important that farmers remember to keep safety in mind when spreading slurry.
Safety guidelines:
- Agitate on windy days;
- Remove all livestock and control pets;
- Open all doors and control access;
- Agitate/ventilate and stay away for 30 minutes;
- Work upwind at all times;
- Do not enter tanks – even when empty;
- Keep tank openings secure at all times;
- If possible, avoid agitating alone.
Farming can be dangerous but measures can be taken to reduce the risk posed to farmers.