Why bother composting bedding instead of spreading it straight on the field

Fresh muck straight from the barn is not the gift to your pasture that it might appear. Spread too early and the nitrogen locks up as soil microbes work on the carbon, the ammonia burns young grass, and any wormer or weedkiller residues travel with it. Composting solves all three problems at once. Heat destroys most weed seeds and pathogen eggs, the carbon and nitrogen settle into a stable form, and you end up with a dark, crumbly conditioner that improves structure on heavy clay as readily as it holds moisture on hungry sandy ground.

For a smallholding, it is also the simplest way to turn a disposal problem into a resource. Straw from the goat shed, shavings from the horse box, soiled poultry litter, hedge trimmings, lawn clippings, spent hanging baskets — all of it belongs in the same heap.

Getting the carbon to nitrogen ratio right

The single biggest reason heaps sit cold and sulky for a year is an imbalance between carbon-rich bedding and nitrogen-rich manure. Aim for roughly 25 to 30 parts carbon to one part nitrogen by volume. Get it broadly right and the heap heats within days.

Useful figures to hold in your head:

• Straw bedding runs around 80:1 — high carbon, slow to break down
• Wood shavings and sawdust are far higher, often 400:1 or more, so use them sparingly
• Horse manure sits near 25:1, cattle manure around 20:1
• Poultry manure is fierce stuff at roughly 7:1 — a little goes a long way
• Grass clippings are around 20:1 and best mixed in thin layers rather than dumped in slimy mats

A practical rule for a mixed smallholding heap is three barrowloads of soiled straw or shavings to one of rich manure or green waste. If the heap smells sour and ammonia-sharp, you have too much nitrogen; add straw. If it does nothing at all and stays dry and pale, you need more muck, more greens, or simply more water.

Building a heap that will actually heat

Size matters more than most people expect. Anything under about one cubic metre will lose heat as fast as the microbes make it. Build to at least a metre in each direction, ideally 1.2 metres tall and wide, and site it on soil or gravel rather than concrete so worms and drainage can do their work.

Layer as you go: a 15–20cm layer of bedding, then a thinner layer of manure or green waste, then a scattering of soil or finished compost to introduce the right microbes. A handful of poultry manure every few layers acts as a starter. Water each layer as you build if the material is dry — the whole heap should end up with the moisture of a wrung-out sponge, damp but never dripping.

If you keep poultry, a separate heap of pure litter is worth having, but treat it as a high-nitrogen ingredient rather than a heap in its own right.

Turning, temperature and timing

Within three to five days a well-built heap should reach 55–65°C. Push a metal bar or a compost thermometer into the centre to check. That temperature range is what kills weed seeds, fly larvae and most pathogens, so it is worth chasing deliberately.

Turn when the temperature starts to fall, roughly every week for the first month, then every fortnight or so. Turning moves the cooler outer material into the middle and re-oxygenates the pile. If it has gone cold and slimy, turn it and add coarse straw. If it has gone cold and dusty, turn it and water it.

In a good season, with regular turning, you can have usable compost in three to four months. Left to its own devices, a heap will still finish, but expect six to twelve months.

Keeping the heap covered through the British autumn and winter

Our rainfall is the enemy of an open heap. Constant soaking drives out air, cools the core and leaches the very nutrients you are trying to capture. From October onwards, cover the heap with a tarpaulin weighted at the corners, or build it under a simple corrugated roof.

Covering does not mean sealing. Leave the sides open so air can move and excess moisture can escape. In a wet spell, check the heap after heavy rain — if water runs out when you squeeze a handful, turn it and mix in dry straw or shavings before covering again. In a dry summer, the reverse applies and you may need to water it.

Winter heaps often stall below 10°C and that is fine. Keep them covered and turn once a month to stop them going anaerobic, and they will take off again in March.

Using the finished compost

Your compost is ready when it is dark, crumbly, smells of woodland rather than ammonia, and you can no longer recognise the original ingredients. Expect the volume to have dropped by half to two-thirds.

• Top-dress pasture in early spring at roughly a barrowload per 10 square metres — it feeds the soil rather than the grass directly
• Spread on the vegetable beds in autumn and let the worms pull it down over winter
• Use as a mulch around fruit bushes and soft fruit canes
• Make potting mixes by sieving and blending with leafmould and sharp sand

One caution worth repeating: a small number of persistent herbicides survive the composting process and can damage tomatoes, beans and other broadleaved plants. If you bring in manure or bedding from off the holding, test a batch by growing a few broad beans in it before spreading it widely.

Get the balance right, keep the heap turned and covered, and you will have a free, steady supply of the best soil conditioner money cannot buy.