The silage-making season is upon us and Limerick City and County Council is advising all farmers of their obligations.
All effluents arising from silage operations must be collected, stored and managed in accordance with the requirements set out in the European Union (Good Agricultural Practice for Protection of Waters) Regulations 2022 (as amended).
The silage-making season is upon us and Limerick City and County Council is advising all farmers of their obligations.
All effluents arising from silage operations must be collected, stored and managed in accordance with the requirements set out in the European Union (Good Agricultural Practice for Protection of Waters) Regulations 2022 (as amended).
Silage effluent is a particularly potent pollutant – (200 times more polluting potential than raw domestic sewage). It is essential that all effluents arising from the silage making process are collected, stored and managed in a manner which ensures that water quality is not impacted.
The following guidelines should be followed:
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Ensure that the silage base and associated collecting channels are free from defect. Where repairs are required seek professional advice. See Department of Agriculture, Food and the Marine building specifications
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S. 128 - Minimum Specification for Concrete Silage Bases
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S.128A – Minimum Specification for Re-Surfacing of Silo Floors
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Only use proprietary sealants where required.
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Wilt the grass prior to ensiling - this helps ensure that dry matter content is at a level where release of effluent is minimized (at least 30% dm should be attained). Cut grass should be windrowed and tedded. Low dry matter grass results in poor fermentation and can result in “slumping” in the pit. This can cause channels to block and effluent to overflow to watercourses or to enter groundwater.
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If possible, cut-grass should be taken to the silage pit in the afternoon (this allows time for dew to evaporate).
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Ensure that grass is kept behind the drainage channels on the base and ensure that the drainage channels are kept free from blockage.
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Ensure that the polythene cover extends beyond the channels.
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Do not overfill pits – this is dangerous from a health and safety point of view and can also result in collapse of the pit. Where the design volume of the pit is inadequate for amount of silage to be harvested, fill pit to design limit and bale the remainder of the cut grass.
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Check regularly to ensure that all effluents are being collected. Ensure that collection tank is fit-for-purpose and is never allowed to overflow.
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Regularly check field drains and streams (throughout the year) to ensure that farm effluents are not being directed away from effluent storage facilities (look for signs of sewage fungus – a grey, dirty looking mass of growth and odour). This is particularly important at silage-making time and when the pit is opened over the Winter period.
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Do not use farmyard manure or any organic material to cover the silage pit. Only clean water is permitted to flow off the silage cover – this to be directed to a clean water drain.
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Directly ensiled grass can release up to 30 litres of effluent per tonne for the first few days after ensiling so keep a constant eye on effluent collection tank.
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Silage effluent can be fed to livestock. Where it is to be landspread it should be diluted at least 1:1 with slurry. Ensure that adequate buffer zones are maintained to ensure waters are protected.
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Where silage infrastructure is in poor condition do not make pit silage. In this instance, only baled silage shall be made. Baled silage shall not be stored within 20metres of any waterbody. Baled silage shall not be stored more than 2-bales high.
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Always consult with Contractor to ensure that best practice will be followed.
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In the event that silage effluent is observed leaking from the pit you must ensure that measures are taken to prevent entry to waters (i.e. break the pathway to waters). You are obliged to report any such issue to the council.
In most situations when silage effluent is perceived to have stopped flowing, the pipe directing silage effluent to the storage tank is turned away from the tank and is then directed to a field drain / watercourse via a pipe. In reality it is very difficult to ensure that only clean water flows through this pipe to the watercourse.
To minimize the risk of polluting matter entering waters there shall be no direct connection between the silage base and any field drain or stream (“breaking the pathway”).
Therefore, when effluent ceases to flow, instead of directing run-off directly to a drain / watercourse via a pipe the effluent should be directed to a sump tank (earthen) on the field. The sump acts as a settlement pond. The contents of the sump may over-spill onto lands or may be landspread using a sprinker system or vacuum tanker. The sump should not be located within 20m of any drain / watercourse.
Farmyards must be kept clean on a continuous basis. There shall be no direct discharge of farmyard run-off to any drain or waterbody (uncontaminated roof water may be piped directly to a drain / watercourse.
Prior to undertaking any of the above you should discuss with your Agricultural Advisor