Horse Manure is a boon to urban gardeners, provided that you can get hold of it.
There are a few caveats to this:
- Horse Manure mixed with straw is much superior to manure mixed with wood shavings. This is because the wood shavings take much longer to rot down and, if placed on the garden, rob the soil of useful fertility whilst breaking down.
- Horse Manure can cause bad problems if the horses were fed on feed contaminated with aminopyralid, which causes serious problems to growing many crops.
Having said that, I have been using manure from a local stables in Northwood for 4 years and have had few problems.
Benefits from applying horse manure, particularly to infertile ground, include:
- An expansion in the population of earthworms in the soil.
- Marked improvements in crop yields of asparagus (20lb vs 12lb on our 5m * 1m permanent bed).
- Ability of rhubarb and comfrey plants to thrive on fresh manure (against most traditional lores but the test of the cake is in the eating, after all).
For me, a pile of 1m*1m*1.5-2.0m requires four trips to the stables, each trip yielding 4 full bags of London Borough of Hillingdon Green Waste receptacles. Thankfully, the stables leave a manure fork in the pile, which resides conveniently at the edge of the customers’ car park.
The ideal scenario is building a pile in August and rotting for 15 months to November, before applying to the bed in which potatoes will be grown. Last summer, however, all the manure was full of wood shavings, so this year’s pile was half constructed in November and half in February, when straw-based manure was abundant.
Three days after completing the pile, the internal temperature was 55C, less than the 70C hoped for, but still a useful temperature for composting.
To learn about how horse manure piles evolve, acquire a soil thermometer and measure the temperature daily – it is quite surprising how consistent the results are. The pile is ready for turning once the temperature drops to 30C.