We have briefly presented the different types of manure in a general article devoted to this modification… Let’s focus here more specifically on horse manure, with its specific characteristics.
Main features of horse manure
A balanced material
The horse is a relatively vulnerable animal.
And we also tend to give it a special status. It is an animal that we qualify as “noble” for which we feel a lot of sympathy (too bad for other animals…).
For these reasons, the bedding (usually made of straw) is changed very often.
This means that this manure is special rich in woody, carbonaceous material (often more than 50% of the total manure).
However, this type of material is ideal for building stable humus, the gardener’s ‘grail’.
In addition, horse manure contains:nitrogen, of the potash and other mineral elements (Calcium, Magnesium… Slightly less phosphorus as we’ll see below), this in balanced proportions, but relatively low (that’s why we classify it as an amendment, and not a fertilizer).
Thus, but also due to its diversified composition* (urine, excrement, straw), it is a balanced supplement, ideal for improving the soil in a sustainable way.
* – Because confusion often occurs, a little precision is needed here: manure alone is not manure… It is just excrement, never to be used alone (composting with other materials is then necessary).
A hot material
Horse manure heats up easily and quickly.
It is therefore especially interesting for heating heavy clay soils.
A lightweight material
It is also a lightweight material.
I know… If you’re towing your wheelbarrows with manure, you’re not agreeing with me…
By this I mean that it is light compared to other manures (especially cow manure) and especially compared to heavy, clayey soil.
It will therefore make this type of soil lighter.
Where to get horse manure?
Horse manure can be obtained from farms near you (there are more and more horse farms everywhere…).
Unless they value it themselves, they will generally be happy to get rid of this “bulky”.
Unfortunately, depending on the origin, horse manure can contain toxic elements, such as chemical dewormers or other drug residues.
It therefore seems important to me to obtain this information from the breeders from whom you want to obtain manure.
Fortunately, more and more breeders are opting for a gentle approach.
Also note that composting eliminates these unwanted elements in a garden. In the absence of manure from “natural” farms, the use of “contaminated” manure remains possible, provided it is composted…
You can also find composted manure (in granules or powder) in most garden centers.
We have seen that horse manure is rich in nitrogen and potassium.
However, it contains relatively little phosphorus.
Mixing with green materials (richer in phosphorus) is therefore a good thing.
You can do this by including it in your vegetable compost.
Or, if you choose to pile up the manure, add and mix grass clippings, RCW or other sized green waste.
The compost obtained will be spread just before the establishment of crops or even at the foot of the crops present (vegetables, flowers, fruit trees, etc.).
Spread horse manure directly on the land.
Heavy soils (but it will also benefit light soils, even if cow manure would be more suitable) will benefit from a good spread of fresh horse manure (meaning recent… And quite warm actually).
During the winter, earthworms and other “degrading” microorganisms will gradually integrate it into the soil as it breaks down.
The manure is then not only good for the life of the soil (you bring food to the inhabitants, at a time when it may be missing…), but also for the structure (these diggers aerate it.) and the richness (supply of mineral elements, building a stable humus).
When to spread horse manure?
Manure can contain germs…
I also strongly advise against spreading manure that is not perfectly digested in the spring, just before the establishment of the crop (even less at the foot of the crops present).
On the other hand, if it is perfectly digested, it remains possible… But we are no longer talking about “manure”, but rather about compost.
However, the best time to spread fertilizer is in the fall.
Amount of horse manure per m²
Horse manure contains urine and has a relatively high ammonia content.
So it should not be misused.
An annual application of 1 to 3 kg of manure per m² is a reasonable contribution, without the risk of ammonia contamination.
Horse manure has a variable density (in particular depending on the proportion of straw and the degree of decomposition) between 100 and 300 kg per m3…
Well… Without having to measure the density of the collected manure, and to keep it simple, let’s say you can more or less spread the contents of a wheelbarrow on 10 m² of soil.
Alternating intake is a good thing.
Also, I don’t necessarily recommend adding fertilizer every year.
In heavy soils, you can alternate adding horse manure and growing green manure every fall.
Or take, for example, a 3-year cycle:
- a cultivation of green manures in the first year, mainly to loosen the soil
- a supply of manure, in the second year, to enrich it sustainably (and at the same time reduce it)
- in the third year: add compost, covered with good mulch to maintain fertility…
Leave the field cleaning residues before spreading.
You are also allowed to bring some green material (cuttings, prunings, vegetable waste, etc.) with you.
Distribute the manure as evenly as possible (at the rate of one wheelbarrow for up to 10 m² per year – so 2 wheelbarrows if you are adding fertilizer every 2 years, or 3 wheelbarrows if you are adding fertilizer every 3 years).
To aid the decomposition process, don’t hesitate to cover the manure with a layer of hay, shredded material, dead leaves or even straw.
Note that it is also possible to apply the manure very lightly into the surface of the soil (by scratching superficially) at least a month after spreading (so that the decomposition process can begin). But it’s work for nothing in my opinion (the earthworms will take care of it). And it’s especially risky (the manure can rot in the ground instead of decaying).
For your warm diapers
Horse manure is the ideal material for the formation of warm layers due to its rapid heat capacity.