Management of Farmyard Manure on farm

Farm yard manure (FYM) from livestock production has always been a valuable source of fertiliser, but just how valuable muck is depends on a number of factors, including how it is stored, whether it is analysed, and how and when it is applied to fields.

FYM contain plant nutrients and organic matter, which is important in building good soil health, which in turn benefits your crops and grass growth and in the long term will provide financial savings if stored and applied at the right time.

One of the main considerations for farmers is how do we store FYM if we want to get the nutrient and organic matter benefit when applied to land and comply with environmental regulations.

Storage

The ability to store FYM rather than use immediately after production enables farmers to spread at the optimum time in line with The Environmental Authorisations (Scotland) Regulations 2018 (EASR) – under Water General Binding Rules.

There are two main ways of storing FYM either within the steading in a constructed midden or in the field in the form of field heaps.

Steading middens:

FYM can be stored in the steading in a structure which is fit for purpose.  The midden / dungstead must have an impermeable floor slab, suitable sized effluent collection tank to collect the rain driven seepage (defined as slurry under EASR) and not be located within 10 m of surface water drainage system.  In some situation empty silage pits can be used to store FYM.  General advice would be only to store FYM on a concrete base as if store on asphalt the seepage (slurry) is known to impact the asphalts quality over time.

Middens can be built with or without walls and in some situations these walls could be designed to weep.  It is essential the seepage generated from the midden is collected and transferred to an effluent collection tank.  In some situations, it might be possible to transfer the midden seepage directly to a slurry storage tank.  Alternatively if the farms liquid (Slurry) storage is limited the rain driven run-off/ seepage  from the midden can be treated in a Constructed Farm Wetland KTR5Constructed-farm-wetlands.pdf  – EASR Water General Binding Rule 33.

To reduce the amount of run-off from the storage of FYM in steading, farmers could consider constructing a roof over the midden.

Field heaps:

Field heaps are the most common method of storage for FYM, but this can lead to loss of nutrients. The main concern is loss of nitrogen, which occurs as a result of ammonia volatilisation – the main pathway – and nitrate leaching.

Ammonia volatilisation can be minimised by covering heaps with a waterproof sheet.

The location of heaps within fields is important and must comply with EASR Water General Binding Rule 18.  The key storage principles to remember are that muck should not be stored on land this is:

• Within 10 m of any surface water, wetland or shoreline
• Within 50 m of any spring that supplies water for human consumption or any uncapped well or borehole
• Waterlogged
• Sloped, unless a sufficient buffer zone is provide to prevent and contaminate run-off entering nearby surface waters, or
• Has an average soil depth of less than 40 mm over gravel or fissured rock

Heaps should be moved every 12 months and a two-year gap should be left before returning to a site.  It is a good neighbour practice to store FYM as far away from residential properties as possible.