Since ancient times, people have used animal waste to improve soil fertility and grow plants organically, without chemicals. However, not all manures are suitable for plants, and there are some things you should be aware of and consider before you begin applying manure to your garden.
If, for example, your soil is biologically active, meaning it has an adequate supply of microbes, manure can make an effective, quick-acting fertilizer if properly applied.
There are different ways to process and apply the waste to avoid damaging your plants. If your soil contains herbicides or poisons that reduce the microbe population, simply adding manure without composting it first won’t produce the desired results and could, instead, have negative effects.
In some cases, the manure, itself, may be contaminated by harmful bacteria, or it may contain pesticide and herbicide residues because those chemicals were used on the animal that produced it or on the food the animal consumed. You’ll also need to consider which animal manure to use, as some are more effective in particular applications than others.
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It’s always a good idea to get your soil tested before you apply any fertilizer. You can test it yourself using a kit you can order online or buy from your garden supply store, or you can get in touch with your county extension office to have it tested.
You’ll want a test that measures microbial activity in the soil because the microbes will be needed to interact with the manure.
Earthworms are a good indicator of healthy soil and microbial activity. If you don’t want to do a soil test, you could simply count the number of earthworms present in one cubic foot of your soil. If there are at least ten, you should be fine.
Still, you won’t have other information you may need to know, such as existing levels of nitrogen, phosphorous, and potassium, the essential nutrients fertilizers provide.
Why is this important? Some manures, like poultry droppings, have very high nitrogen content. Adding them to a soil that already has high levels of nitrogen could damage your plants.
Avoid using fresh manure on existing plants, especially if it is high in nitrogen content. Not only might this harm the plants, but it could also contaminate them with dangerous bacteria.
If you’re applying manure in a vegetable garden, introducing the kind of harmful bacteria present in some fresh waste is a really bad idea. If you want to use fresh manure, bury it in the garden several weeks before planting. That will give it enough time to interact with microbes and break down into compost. Otherwise, compost the manure before you apply it to your plants using a mix of one part manure and two or three parts of other organic material such as kitchen waste, plant matter, or store-bought natural compost.
What Is The Best Manure To Use In Garden?
When choosing manure for your gardening, you first need to consider the source. Different animals have different diets and digestive systems, thus their waste products vary as well. Following are some popular options.
Birds’ urine is mixed with their feces. Sorry, but you need to know this because it gives their manure a high nitrogen content and makes it a poor choice for direct application to plants. It does, however, contain a good balance of the three essential nutrients, nitrogen, phosphorous, and potassium, so it is a good choice for composting.
This is not really a good choice for burying in your garden before planting. Horse poop can contain a lot of weed seeds that horses don’t fully digest, so you might end up with a weed garden if you bury fresh horse manure.
It does, however, have good levels of nitrogen and potassium and is a great candidate for composting. Another advantage is that you can often get it free from stables or racetracks and, if it comes from stalls, it probably also includes a good mix of other organic material like hay and grain. This gives you a head start on composting.
Old-timers often preferred sheep waste to any other. It has a good mix of nitrogen, phosphorous, and potassium and is an excellent choice for composting.
This is probably what most people think of when manure is mentioned for gardening. Garden supply stores typically sell cow manure blends. Some potting and gardening organic soil mixes have substantial amounts of cow manure–so much so that, even though it has already been composted, it gives off that cow poop aroma when wet.
Cow manure also provides a good, balanced mix of nitrogen, phosphorous, and potassium. It is, however, another good example of why you shouldn’t apply fresh manure to existing plants, especially those intended for human consumption. A potentially deadly strain of E. coli bacteria has been known to spread to humans from fresh cow manure.
Although not everyone owns rabbits or has access to a source that can provide this natural fertilizer in large amounts, rabbit manure is a great soil fertility booster. In fact, many even label it as the best animal manure for plants.
Rabbit manure is twice as rich in nutrients as chicken manure and four times than horse or cow manure. It is also not as smelly as other animal wastes. Moreover, rabbit poop is among the few manures that you can utilize fresh without burning the plants (source).
Hence, if you own bunnies, you can use their waste in the garden without having to wait months for it to go through the composting process.
Zoo and circus manure
Zoos and circuses often give away animal manure from elephants and other plant-eaters. Because their diets are similar, the manure of these animals should be similar to that of a horse, but it will be a mixture from a variety of sources and there is no way to know for sure.
If you’re thinking of getting manure from a zoo or circus, try and verify that it does not include the manure of meat-eaters. Manure from animals that consume meat is more likely to contain harmful parasites and bacteria, although composting should take care of that if done correctly.
Although the manure of the animals mentioned earlier are most common used as fertilizers due to their high availability, there are also other animals which manure can be utilized to improve the qualilty of your soil.
Among these, you can compost the waste of guinea pigs, hamsters, bats, gerbils, alpacas, llamas, deers, and so on. In general, you can use the residue of any animal whose diet is based entirely on vegetables or at least in large part.
Is Human Waste Used As Fertilizer?
Also referred to as “sludge,” human waste can be composted and used to feed your plants – even the ones you eat. Although using human poop as plant fertilizer is controversial nowadays, this has been done since ancient times.
If any of you live “off the grid” and have composting toilets, you may already be using this. For the rest of you, however, you may need to contact your local wastewater treatment facilities if you really want to try this.
In 1989, Texas’ capital city of Austin introduced “Dillo Dirt™,” named after the official small mammal of Texas, the nine-banded armadillo. Dillo Dirt is a composted mix of sludge from the city’s wastewater treatment plant and yard clippings picked up curbside by the city’s Resource Recovery Department. Although Dillo Dirt meets state and EPA requirements for use in all applications including vegetable gardens, many find it a bit off-putting.
Many are against again using human waste in gardens because we have an omnivorous diet. Hence, it can contain many bacteria, viruses, and other microorganisms that can cause diseases. However, when the waste is properly composted, it generates temperatures between 55 to 77°C (130 – 170°F), which should be sufficient to kill any pathogens according to the description of Dillo Dirt.
Basically, if it’s manure, you can probably use it to fertilize your garden. You must, however, take precautions. Some manures can be used fresh from the source, usually by burying them in the garden weeks before planting to allow them to naturally decay.
Many can be applied directly to plants, but only after composting. Avoiding manures produced by meat-eaters, including humans, is probably a good idea unless you really know what you’re doing or trust your local supplier.
Gardening is good exercise and all that manure has to go somewhere, so give it a try.
Although manure is a great natural fertilizer, if you don’t grow any herbivores around your house, you may be interested in reading our guide on making compost at home out of your kitchen scraps and other biodegradable household items that you regularly throw away.