Manure can be a very valuable addition to your permaculture garden. As part of compost or mulch, it can add lots of beneficial nutrients to the soil, as well as helping the soil retain moisture. Not only that but you are recycling a supposed ‘waste’ product.
Not all manures, however, are created equally. The digestive systems of different species of animals processes food in different ways, meaning their waste products vary in terms of the nutrients they can give to a soil, and hence to plants. These different properties also mean that they can require different treatment by the permaculturist to make them effective additions to the garden.
If you keep livestock on your permaculture site, you will have a ready supply of manure that you can utilize in your growing beds. If, however, you are not raising animals on-site, you should be able to source manure from local suppliers. Before you consider purchasing manure, ask at farms and stables in your area. They will more than likely be pleased to let you take some manure of their hands, and it is a good way of making connections in your local community. You could perhaps offer to exchange a regular supply of manure for a proportion of your subsequent harvest.
Below are some of the more common types of manure that you may be able to source for your site. For most of them, it is preferable to compost the manure or, at least, wait until it is well aged. This allows pathogens to die off, and the manure ‘mellow’ so that it doesn’t overwhelm or burn plants.
Cows are ruminants. This refers to mammals that break down plant food in a stomach which has four compartments, and who chew the cud – regurgitating semi-digested food and further breaking it down in the mouth to attain the maximum nutritional benefit from it. (Indeed, on average, it takes 18 days for food to pass through the cow.) Because this method of consumption is intended to extract as many nutrients as possible, by the time the food passes through the animal and is deposited as manure, it is not very nutrient-rich.
What it does contain, though, is a lot of microorganisms and enzymes. Each of the four parts of a cow’s stomach has different bacteria in it to perform a different function, and some inevitably leave with the manure. And because these microorganisms thrive on digesting organic matter, they are great additions to soil and compost.
Interestingly, being deposited outside of the animal may actually boost this activity. Within the animal’s digestive system, the processes are anaerobic, but once outside the cow, the oxygen in the air causes the enzyme and microorganism activity to become aerobic, and so helping release more nutrients when added to compost or soil. As such, cow manure acts as a great soil conditioner, increasing the amount of humus in the topsoil, and in turn promoting strong plant growth (making it good as part of a compost for seedlings).
Horse droppings are reasonably nutrient-rich (certainly in comparison to cow manure) but they are significantly high in fibre. This makes them a good binding agent to help maintain the integrity of soil structure and bind elements together within compost. This strong structural cohesion makes horse manure one of the best manures for adding to layered mulches.
If you source horse manure from a local stables or stud farm, ask about any treatments that have been used on the stables where the manure has been collected. Many stables, particularly commercial ones, use pesticides and fungicides in stables to keep bedding pest free, and you don’t want to be introducing these inorganic materials into your compost. Also ask about antibiotic use, as these elements can remain in manure and you should avoid introducing them into your food garden.
Sheep and Goats
Sheep and goats also belong to the ruminant family, but their manure tends to be more dehydrated than that of cows, as their digestive systems extract more of the moisture from their food. Sheep and goat manure is a particularly good source of potassium and nitrogen, two elements essential to healthy plant growth. Potassium is used by plants to make their stalks, stems and root fibers strong, so the high levels of the element in sheep and goat manure means they are particularly useful in a compost for plants that grow tall, such as sweet peas.
Chickens are the most common livestock animals kept on permaculture smallholdings. They provide the gardener with many products, including meat and eggs, pest control, soil turning and grazing, heat energy and enjoyment of their personalities and expressions of behaviour. They also, of course, provide a source of manure – as much as 10 kilos per bird each year.
The urea present in the droppings of chickens makes the manure rich in nitrogen (the same is true of ducks) while also providing good levels of phosphorous. Both elements are essential to plants, and in poultry manure they are in a form that plants can use immediately. Too much nitrogen can burn plant roots, so poultry manure needs to be composted well before use of the garden, but once on the beds, it will help promote strong leaf growth and fruit development.
Rabbits and Guinea Pigs
Manure from these animals is beneficial primarily for its nitrogen content. It is good for composting particularly if added to the pile along with some of the newspaper shreds or straw that is used for bedding. The small, pellet-like nature of droppings from rabbits and guinea pigs means that you can use them directly on garden beds, and they break down quickly so that plants can access their nutrients in the soil.
Besides these types of manure, you may be able to source more exotic droppings. Some zoos give away or sell manure from elephants and rhinos that can be used in gardens, as long as it has been well aged or is composted. It can be tempting to use dog and cat droppings as manure, but this should be avoided as these are likely to contain pathogens that are harmful to humans, and which remain even after composting.