Call it shit, crap, poop, or dung.
Whatever you call it, composted manure is one of the most nutrient-rich, sustainable amendments you can add to your garden.
Many types of animal manure are rich in the nutrients all plants need — nitrogen, phosphorus, and potassium — plus microbes that are great for healthy soil. And, importantly, composted manure provides all those benefits in a form that your garden soil digests over time, as opposed to the quick hit of macro-nutrients that some synthetic fertilizers offer.
There are, however, some disadvantages and concerns involved with using manure in home gardens.
First, it’s important to understand the stages that manure goes through. Fresh manure is high in nitrogen compounds and ammonia that can burn plants and initially inhibit seed germination. Aged manure has been stored for at least six months, allowing some of that nitrogen and ammonia to break down. It’s still nutrient-rich but can also still burn plants. To be considered “composted,” manure must be heated to 145 degrees Fahrenheit and turned enough so that the entire pile has heated through.
While manure can be a great source of nutrients, it does also have some drawbacks. While we tend to think of manure as organic matter, if it comes from non-organic farms or other sources, it may contain residue of pesticides, antibiotics, or other medications that were given to the animals.
In addition, if it was not composted to a high enough degree, it may carry harmful pathogens like E. coli, listeria, or salmonella, which can be particularly dangerous for children. And manure that has not been completely composted is notorious for being a source of spreading weed seeds, which can turn your garden beds into a weed patch.
In spite of those drawbacks, manure can be a useful addition to your soil if you practice a few simple tips:
- Never use raw manure of any kind in your home garden.
- Don’t use manure from cats, dogs, or other meat-eating animals in the garden. They can contain harmful pathogens. And (need I really say this?) never use human manure in the garden.
- If you use aged manure, it should be aged for a minimum of six months, and you should wait at least one month following application before planting.
- If you use composted manure, apply it at a rate of 40 pounds per 100 square feet, and work it into the soil to a depth of 6 to 9 inches.
- If you want to obtain fresh manure for composting, the best sources are local farms, zoos, or stables. Manure composts best when it is mixed with bedding materials like straw. Be sure to wear gloves and washable rubber boots when handling fresh manure, and wash your hands carefully afterward.
- Want to know which animal produces the most nutrient-rich manure? Rabbits! Next on the list are chickens, followed (in order) by sheep, horses, cattle, ducks, and pigs.