How to Add Manure to Compost
Manures can be really handy for composting projects. Animal products tend to be high in nitrogen, which helps bacteria break down other compost ingredients. This speeds decomposition and heats up the pile. Manure is a helpful ingredient when creating “hot” compost piles. Hot composting happens when the pile reaches 135 degrees Fahrenheit for a few days, achieving temperatures needed to kill garden pests and plant diseases.
When selecting a manure for composting, be sure to use vegetarian manures rather than carnivore waste. Cats and dogs are carnivores, and their wastes shouldn’t be composted. Cows, horses, pigs, goats, sheep, poultry and rabbits are vegetarian, and their waste is excellent for composting. Remember that any animal waste can carry diseases that make humans sick, so be sure to wear gloves when handling manure.
Horse and donkey waste tends to have the least nitrogen (lowest carbon to nitrogen ratio) of the groups compared here, which means that the manure may not heat up a compost pile as easily as other animal products. Good addition to “cold” compost projects. C:N ratios range from 22:1 to 50:1.
Rich in nutrients and a good addition to hot composting projects. It can be messy to harvest fresh manure, but the dry “cow pies” are easily handled. C:N ratios from 10:1 to 30:1.
Chicken (Poultry) Manure
Although poultry litter can be very smelly and difficult to handle, it is really valuable in the landscape. Very high in nitrogen and other macronutrients that plants love. Great for hot composting projects. C:N ratios from 3:1 to 10:1.
Rabbit waste is very dry and is usually quite odor free. This high-nitrogen manure is a good ingredient for hot composting projects. Especially handy if you have a friend or family member who has a pet rabbit. Both the pellets and bedding can be added to the compost pile. C:N ratios from 4:1 to 10:1.
Whatever the source, fresh manure should go through a two-step composting process. First, mix the manure with a good source of carbon, like straw, sawdust or wood chips. Depending on the farm, the manure may have been mixed with the animal’s bedding, which is usually a good source of carbon. Keep moist and mix regularly. When the pile cools down, the composted manure is ready to add to other composting projects.
It’s a good idea for eager beginners to get experience using store-bought composted manure before rushing to collect fresh manure from the nearest farm. This will save the need for pre-composting at home, and the composted manure will have fewer potentially harmful bacteria than fresh manure. Many nurseries, garden centers, co-ops and box stores carry a variety of composted manures.