In this article, CAFRE’s Ciaran McKay discusses silage making to minimise effluent production and maintaining and managing silage and effluent storage facilities.
Consider appropriate management of silage effluent and carry out silo maintenance checks before ensiling grass silage.
Silage effluent is a potent pollutant that can cause serious harm to watercourses if not correctly managed.
Silage making to minimise effluent production
Its production is mainly dependent on the dry matter of the crop being ensiled.
As it represents a loss of readily available nutrients, minimising the amount produced should be a priority.
Aim to cut the crop as dry as possible and after cutting, try to wilt for 24 hours.
These measures will increase crop dry matter, thus reducing the volume of effluent produced and improving the quality of the silage.
Grass ensiled above 25% DM will produce very little effluent. The vast majority of effluent will be produced in the first seven to ten days after ensiling.
It is particularly important to be vigilant at this time and ensure you collect all and store appropriately.
Maintaining and managing silage and storage facilities
As silage effluent is corrosive, before filling the silo, inspect the walls and floor to ensure they are free from cracks, are impermeable, and no effluent can escape. Carry out any necessary repairs.
Consider lining silo walls, particularly at joints, to protect them from corrosion, help seal the silo and improve silage quality. Earth banked silos must be lined with an impermeable membrane.
All silos must have a channel to collect and must be kept clear of debris to prevent overflows.
Direct effluent to a suitable storage tank using channels or pipes. Roofed silos will produce less effluent than unroofed silos as there is reduced run-off entering collection tanks.
Store round bales in fields and on permeable hard-core areas not less than 10 m from any watercourse.
If you place impermeable surfaces, such as concrete, collect any produced and manage in the same way as effluent from a silage pit.
Effluent collected and stored can be spread on land, always ensuring it is diluted before spreading, to prevent leaf scorch.
Only spread when weather conditions are suitable and allow a buffer zone of 10 m from watercourses or 3 m if using Low Emission Slurry Spreading Equipment (LESSE).