Slurry is a valuable source of nutrients and when used appropriately, can help to reduce the reliance on bagged fertilisers.
However, it’s also a highly polluting material that must be managed and contained securely. When looking at slurry storage on farm, the options are above ground tanks, below ground concrete tanks and earth bank lagoons with sheet liners. You also might want to look at ways to keep clean and dirty water separate around the steading and consider Rural SuDS systems as a way of treating lightly contaminated water, instead of putting additional liquid into your slurry storage system.
Climate change projections suggest we will experience warmer, wetter winters. This could increase the proportion of dirty water and slurry we have to deal with around the steading.
Following heavy rain, take a look at the route runoff takes around the steading or areas where water accumulates. Could you reduce the volume or divert clean rainwater runoff?
- Roof water – make sure gutters are clear and fitted to serviceable downpipes to get the water straight into the drains and off the steading. Some farmers are already fitting larger sized guttering and down pipes on new buildings to deal with increased rainfall.
- Is ‘clean’ rainfall contributing to your collection systems? Calculations on a SW Dairy farm suggested that this was costing around £0.93/m3 to handle, store, transport and spread.
- A constructed farm wetland may be suitable to take lightly contaminated water from around the steading, rather than diverting to slurry collection systems. Other RSuDS (Rural Sustainable Drainage Systems) may also be worth considering and could attract AECS grant funding support.
- Risk Assessment for Manures and Slurry (RAMS) - Where possible, make sure slurry storage systems are empty going into the housed period. Use a RAMS map to identify low-risk areas for spreading, should you be forced to put slurry out over the winter months with no crop demand.
The Scottish Government's 4 Point Plan contains other practical ideas to make best use of nutrients and calculate and reduce rainwater volume around the steading.
Increasing on-farm slurry storage facilities and AECS funding opportunities
The 2019 round of SRDP Agri-Environment Climate Scheme is open. Funding is available for slurry storage for farms within targeted areas and holdings. The available grant for storage is up to a maximum award of £30,000 towards increasing on-farm slurry storage capacity (to meet but not exceed 6 months storage at current stocking levels). Many farmers who have already secured funding have opted to construct a lined slurry lagoon, but the funding is available across other storage systems e.g. above ground storage towers and below ground concrete tanks.
When calculating if additional slurry storage is required, a Farm Waste Management Plan (FWMP) should be produced which takes into account livestock numbers, ages, housing period and current storage capacity. Effluent from silage clamps, yard scrapings from collecting or loafing areas and parlour washings should also be accounted for in your FWMP. To cut down pressure on storage, clean and lightly contaminated water around the steading could be dealt with separately by a Rural SuDS, as keeping excess water out of your storage tank means more space for slurry. There can be financial savings to be made too from the reduced time and energy required to pump or spread the additional liquid.
There are a number of rules and regulations governing the construction of new slurry storage facilities, and Scotland's Farm Advisory Service has produced a useful 'Frequently Asked Questions' sheet for regular queries surrounding the construction of slurry lagoons.
If applying for AECS funding, there is a requirement for a copy of your FWMP and a steading risk assessment plan, but these are documents all farms should have on file and review regularly. A Risk Assessment for Manures and Slurry (RAMS) map is another document that all farms should have and share with anyone who may be spreading any form of manure or slurry on the holding.
- Farm Waste Management Plan
- Steading Drainage Assessment
- RAMS – how to complete a Risk Assessment for Manure and Slurry Map
- Slurry Lagoon Storage & Construction Frequently Asked Questions
- Rural Sustainable Drainage Systems: A practical design and build guide for Scotland's farmers and landowners
- Livestock manure and silage storage infrastructure for agriculture (C759)
- Code of Good Agricultural Practice for reducing ammonia emissions.
- The Scottish Government's 4 Point Plan
- Scotland's Farm Advisory Service - Podcast: 'Slurry Lagoons - More than just a hole in the ground'