Horse ownership brings responsibilities that go beyond animal care and pasture management. Like all livestock enterprises, equine holdings also have legal obligations under the Nitrates Regulations to prevent nutrient pollution and protect water quality.

Manure from equines contains nitrogen and phosphorus, and if it is not managed correctly it can contribute to pollution of rivers, lakes and groundwater.

Poor manure management also affects pasture quality, increases flies and parasites, and can create animal health issues.

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The good news is that with proper storage, spreading and paddock management, horse manure can be a valuable resource rather than a problem.

Nitrates rules

A common misunderstanding is that nitrates regulations only apply to cattle, sheep or pigs.

The rules apply, however, to all agricultural land where livestock manure is produced, stored or spread, including land used for horses, ponies and donkeys.

The law makes no distinction based on livestock type.

This means private equine owners, livery yards, riding schools, stud farms and equestrian centres are all subject to the same requirements as other livestock farmers.

Even owners with just one or two horses must comply if manure is stored or spread on land.

Where land is receiving agricultural payments, nitrates compliance forms part of cross-compliance and breaches can result in penalties or payment reductions.

Even where no schemes are involved, following the rules helps protect local water quality and reduces the risk of enforcement action.

Inspections increasing

Local authorities are responsible for enforcing the Nitrates Regulations, and inspections on farms where manure is stored or spread are becoming more frequent. A significant proportion of inspected holdings are found to have some level of non-compliance.

Equine owners should be ready for inspection and keep basic records, including:

  • Where manure is stored
  • When and where it is spread
  • Quantities spread or exported
  • Soil test results and nutrient plans, where available
  • Good records don’t just tick a regulatory box – they help show that manure is being managed responsibly and can make inspections far more straightforward.

    Manure storage

    Horse manure can be a useful organic fertiliser when handled properly. However, unmanaged or poorly stored, manure is a major source of nitrate and phosphorus losses, and a source of parasite and other disease-causing organisms.

    All equine owners, regardless of stocking rates, must store manure in a way that prevents runoff or seepage. Manure heaps in fields outside of the closed periods below should:

  • Be located well away from watercourses (20m from all waters including dry drains), drains and wells (50m from any domestic well)
  • Be on an impermeable base
  • Be managed to prevent nutrients washing into surface or groundwater
  • Covered storage or properly managed composting reduces nutrient losses, odours and flies. Composting can also reduce parasite survival, but only if done correctly.

    Where anthelmintic resistance is present or composting is poorly managed, spreading manure back on land can do more harm than good. Testing multiple samples from different parts of the manure heap for parasite survival is strongly advised.

    Equine holdings may need to invest in suitable storage facilities or arrange for regular removal of manure.

    Exporting manure to a neighbouring farmer is an option, provided it is used within nitrates limits and the movement is recorded. Since January 2025, exports of organic nutrients must be notified through DAFM’s online system within four days. The Targeted Agriculture Modernisation Scheme may be a mechanism for eligible candidates to avail of funding to assist with upgrading of storage infrastructure.

    Dumping manure or spreading it in an uncontrolled manner is an offence and is a common cause of enforcement action.

    Closed periods

    The Nitrates Regulations set out closed periods during which farmyard manure (FYM) cannot be spread under any circumstances. Field storage of FYM cannot take place during the periods listed.

    Prohibited application periods: Farmyard manure

    Zone prohibited period

    A - Carlow, Cork, Dublin, Kildare, Kilkenny, Laois, Offaly, Tipperary, Waterford, Wexford, Wicklow. 1 November -12 January

    B - Clare, Galway, Kerry, Limerick, Longford, Louth, Mayo, Meath, Roscommon, Sligo, Westmeath 1 November-15 January

    C - Donegal, Leitrim, Cavan, Monaghan 1 November-31 January

    During these dates, spreading is prohibited regardless of ground conditions. Adequate storage must be available to hold manure for the full closed period and ideally extra capacity for prolonged wet weather. Storage during these dates must be on concrete, with collection channels or walls and all seepage and rainfall from the concrete area to be collected in a tank.

    Storage calculations for horses are based on 0.59 cubic metres per animal per week, assuming 4kg of bedding per horse per day. Where manure is mechanically stacked in unroofed stores, a compression factor may reduce this to 0.354 cubic metres per animal per week utilised where a tractor or loader is used to stack. This reduction does not apply where manure is stacked manually.

    Outside closed period

    When spreading is allowed, conditions still apply. Manure must not be spread:

  • On waterlogged, flooded, frozen or snow-covered ground
  • When heavy rainfall is forecast which means rainfall meeting the criteria for yellow, orange or red rainfall warnings issued by Met Éireann
  • Within buffer zones of drains, streams, lakes or wells
  • Spreading must also match the land’s ability to absorb nutrients. Localised over-application on small paddocks is a common issue on equine farms and can quickly lead to pollution.

    The maximum permitted nitrogen loading from livestock manure is 170 kg N per hectare per year, unless operating under a derogation.

    Most horse enterprises operate well below this limit, but it is still important to avoid concentrating manure on small areas.

    Annual nitrogen excretion rates for horses are lower than cattle but still significant. An adult horse produces around 50 kg of nitrogen per year, while ponies and donkeys produce slightly less. Records of where and when manure is spread should always be kept.

    Nutrient excretion rates for equine livestock:

    Livestock type total nitrogen kg/ year 170kg stocking rate = number of equines 100kg stocking rate = number of equines

    Reduced storage

    Reduced storage allowances may apply where horses are outwintered, provided strict conditions are met.

    At least six weeks’ storage must be available for all housed animals, and prohibited spreading periods must still be respected.

    One hectare of accessible grazing land is required per outwintered horse. If, for example, 15 horses are on a holding with storage for 10, five may be outwintered provided five hectares are available.

    However, if more horses are housed at inspection, storage requirements will be recalculated.

    Reduced storage only applies where:

  • All outwintering land is part of the holding
  • Horses have unrestricted access to the land
  • Nitrogen loading does not exceed 100 kg N/ha
  • Severe poaching does not occur
  • Storage reduction matches the number of outwintered horses
  • Paddock management

    Horse paddocks are particularly vulnerable to nutrient build-up. Manure tends to accumulate around feeders, water troughs and gateways, leading to bare ground, runoff risk and increased disease-causing microbial contamination.

    Regular dung collection, avoiding overstocking, rotating grazing and maintaining grass cover all help reduce nutrient losses. Good paddock management also lowers parasite burdens and improves horse health.

    Soil testing Soil testing is one of the most effective tools available to guide nutrient use. Nutrient management plans help match manure applications to crop and grass demand, reducing waste and lowering fertiliser costs.

    While mandatory for derogation farms, nutrient planning is good practice for all equine holdings and can deliver real financial and environmental benefits.

    Other obligations

    While the focus of this article has been on farmyard manure management, there are additional obligations in the management of any slurry or soiled water on the farm, and it is important to note that animals housed or managed on non-concrete bases inside the farmyard are automatically considered in breach of nitrates regulations.

    A shared responsibility

    By managing manure correctly, complying with nitrates rules and keeping good records, equine enterprises can protect water quality, improve pasture performance and reduce regulatory risk.

    Good nutrient management is not just about compliance, it is about safeguarding land, livestock and local communities for the long term.

    For more information, contact teagasc.ie