Horse Manure Management: Legal Facts & Composting Guide

No one likes mucking out, and a muck heap is an unwanted but necessary part of horse keeping. However, managing horse manure goes far beyond just piling it up or calling a farmer to spread it occasionally. Proper legal and environmental handling is essential to avoid fines and maintain good relationships with neighbours and the environment.

Understanding Horse Manure as Waste or Non-Waste

Horse manure is not always classified as waste under UK law. To avoid this, you must meet certain conditions:

• It is used strictly as a soil fertiliser.
• Its use is part of lawful spreading on clearly identified agricultural land parcels.
• Its storage matches the needs for spreading operations on agricultural holdings, whether your own or another's.

If all these conditions are met, manure is not legally considered waste. Without a designated spreading area, manure becomes classified as solid waste subject to waste disposal laws.

Handling Manure as a Horse Owner or Small-Scale Stable Operator

The average horse produces approximately 7.5 tonnes of manure annually, not counting bedding and other waste mixed in. Different bedding types affect disposal options, so choose wisely, prioritising those that compost well and have less environmental impact.

Composting is the Environment Agency's preferred and most cost-effective method for small-scale operations. While composting is straightforward, it requires adherence to regulations to ensure the heap remains manageable, legal, and environmentally friendly.

Step-by-Step Guide to Building a Compost Heap for Horse Manure

Step 1: Choosing Materials

Use straw as your primary bedding for composting, as it breaks down effectively. Wood chips, shavings, and sawdust are also suitable but compost more slowly. Avoid mixing household waste or food scraps into your heap, as that turns the entire pile into mixed waste. Additionally, manure and bedding from sick horses should not be composted due to potential pathogens.

Step 2: Managing Bedding Systems

A deep litter system works best when composting everything, but requires careful management to prevent ammonia build-up and wet conditions that could harm horses. Alternatively, collect manure and bedding in a designated area until ready to add to the heap. Some stables maintain two heaps: one active composting pile and one being built up.

Step 3: Building the Pile

Construct your compost heap about 2.5 metres wide and 2 metres high. This size allows enough heat development and air flow necessary for effective composting. Cover the pile with a woven textile fabric specifically designed for composting to allow air circulation while limiting light and rain exposure.

Step 4: Enhancing Decomposition

Add around 10% soil to your heap to stabilise decomposition and introduce microorganisms that accelerate the process. You may also use commercial compost bacteria or add matured compost to kickstart activity.

Step 5: Moisture and Aeration

Maintain a damp but not soggy pile to encourage bacterial activity. At the start and in dry spells, watering lightly is beneficial. Turning the heap periodically aerates it, shuts off odours, and prevents hot spots. Too wet conditions should be avoided to prevent runoff problems.

Step 6: Monitoring Temperature and Turning

In warm weather, the heap should heat up rapidly, potentially within three weeks, decreasing in volume as material breaks down. Once cooling begins, turn and re-moisten the heap as needed to maintain composting conditions.

Step 7: Final Curing and Application

Move the compost pile so its base is in contact with soil to allow worms and soil organisms to aid final decomposition. Let it stand for a couple of months until the texture, colour, and smell resemble rich soil rather than manure. Fully cured compost is a valuable fertiliser rich in nitrogen, phosphorus, potassium, and beneficial microorganisms.

Important Dos and Don'ts for Horse Manure Management

• Do not burn horse waste, as it is illegal and harmful.
• Avoid any runoff from manure heaps, washing hay, or rinsing stables. If runoff risk exists, store heaps on concrete with appropriate drainage.
• Do not site heaps closer than 10 metres from watercourses (rivers, streams), and maintain at least 50 metres distance from wells, springs, or boreholes to prevent contamination.
• Avoid placing heaps near field drainage systems where pollutants could leach into water sources.
• Apply compost only within ecological limits to prevent nutrient overload harming waterways.
• Siting heaps consider neighbours and public spaces — avoid creating nuisance smells or blocking footpaths and views.

By following these practices, you ensure that manure management is responsible, sustainable, and compliant with UK regulations.