Did you know that the US and EU each produce a whopping 1.4 billion tonnes of manure a year? *
In short, that’s an extraordinary amount of organic material that, if used correctly, can enrich our soils and nourish our plants in extraordinary ways.
There’s so much around that it’s often free (if you collect it) or very cheap (if you have it delivered).
At the same time, there are risks to using manure (which we’ll come to later in this article).
However, people often get confused about the difference between compost and manure.
That’s understandable, as there is considerable overlap between the meanings.
But before we understand how we can use manure and compost to benefit our soil, (and how to avoid those risks!) it’s key to understand those differences.
So whether you’re a keen composter or an aspiring gardener, let’s take a walk through the differences.
What is compost?
Compost is a partially rotted-down organic material that is used to provide nutrition to soil and plants.
Its benefits are a little more complicated – and also widely misunderstood.
Many people think its main role is to provide nutrients directly to plants.
It’s true that it does this to some extent, but its other benefits are probably more important.
These include improving soil structure and feeding microorganisms such as Mycorrhizae Fungi.
What is manure?
Manure is animal droppings and pee that are used to enrich the soil. It may or may not be composted first.
Some sources argue that there is a difference between composted manure and regular compost.
However, I’d argue that because manure is also an organic material, if it is composted it is also compost! However, different people do use the terminology in different ways.
Historically, manure was often considered a vital ingredient in the compost heap
Still, that perception has changed in recent decades, and many people make perfectly good compost without using manure.
That’s probably because many of us now live in urban areas and simply don’t have easy access to manure.
Manure can also contain herbicides. Some herbicides don’t break down until they are in the soil, and these can have a major impact on the health of our plants.
What is manure compost?
Manure compost is simply compost that is made from composted animal excrement.
Typically, though, this will often also contain a high carbon source such as straw, which is used to balance out the high nitrogen found in manure.
What’s green waste compost?
So far we’ve seen that manure can be composted, and regular compost can contain manure.
Fortunately, we do have another term for compost that doesn’t contain manure!
Green waste compost is compost that is made from non-manure sources (i.e. plants!) It includes materials like grass clippings, leaves, branches, twigs, weeds, and other plant-based materials.
What is humanure?
Humanure refers to human urine and excrement which is composted.
You do need to take extra care when composting humanure because of the risk of pathogens.
At the same time, properly composting humanure offers us the opportunity to reduce harm to the environment.
Related article: How Humanure Could Help Change the World
What’s green manure?
Green manure refers to plants that are grown in the ground to improve the soil.
Traditionally, these plants are then dug into the ground, but in a no-dig environment, they can be cut at the roots and added to the compost heap.
Green manure can:
- prevent erosion when the soil would otherwise be bare
- suppress weeds
- increase organic matter in the soil
- increase nitrogen levels
- draw nutrients from deep in the soil.
Different plants have different benefits.
For example, legumes extract nitrogen from the air and fix it in the soil (although you have to cut them before they fruit to get the benefit.)
I personally like using green manure to cover areas of my vegetable patch when it would otherwise be bare.
Some types of green manure can also be edible. For example, I once bought field beans from GreenManure.co.uk with the intention of using them as green manure, but they looked so appetizing that I ended up harvesting and eating them instead.”
Five years later I am still munching on their descendants! I’ve found them to be tougher, more reliable, and more productive than autumn-planted broad beans such as Aquadulce (although they do take a bit longer.)
GreenManure.co.uk has a good guide to the different types of green manure, and the benefits of each one.
Summing up
If you have access to a (clean) source of manure, you’re in luck.
High in nutrients, it makes a fantastic amendment to the soil and is particularly good for hungry vegetables like courgettes.
It is best composted first, as this reduces pathogens, kills weed seeds (if hot composted), and provides a more stable soil amendment.
It also works well when combined with green materials in your compost heap.
Just remember to be careful about where you source it from, and to test it before use!
Footnotes
* Pagliari and Wilson (2020) stated that the USA produces up to 1.4 billion tons of manure, while Loyon (2016) gives the same estimate for the EU.
Read next
How to Compost Manure: Learn everything from how to compost manure to the nutritional values of different manures.
Use Manure, But Compost It First Say Researchers: Scientists explain the value of manure, and why it is best composted before using it.
An Introduction to Humanure: Learn what humanure is, and why composting it is so beneficial to the environment.
External resources
Rodale Book of Composting, (1992) Ch. 7, Using Manure: An introduction to using manure along with comparisons of different types of manure.
Weedkiller in Manure: The Royal Horticultural Society gives a good overview of issues with weedkillers (predominantly aminopyralid) in compost.
Properties of manure: An in-depth overview of different types of manure provided by the Manitoba Agriculture, Food and Rural Development department in Canada.