Using manure as fertilizer can be great for your garden.
Whether you’re using cow manure fertilizer, chicken manure fertilizer or horse manure fertilizer, the results are the same.
You can make your plants very happy with manure fertilizer.
But before you start using manure in your garden, there are a few things you should know about using manure as fertilizer.
Manure fertilizer can do lots of wonderful things for your garden soil and for your plants.
All manures contain the big 3 nutrients – nitrogen, phosphorus and potassium. But they also contain an abundance of many trace minerals and nutrients.
Incorporating manure into your garden soil will also add lots of organic matter to your soil, and that’s a very good thing.
It will help to improve the tilth (soil structure) of your soil, which will help your plant’s roots to breathe easier (yes, roots breathe!).
The organic matter that manure fertilizer adds to your soil will also improve your soil’s water-holding capacity.
What are the negatives to using manure as fertilizer?
Here are some of the potential negatives that you could encounter when using manure fertilizer:
If the animal that so cooperatively produced your manure for you was chowing down on weeds that contained mature seeds, then that manure probably contains lots of weed seeds just raring to sprout.
The seeds can pass through the animal’s digestive tract unharmed, exiting the nether region of the animal in a pile of poop that’s a perfect incubator for weed seed germination.
Using that manure as fertilizer could place you on the losing side in your eternal battle against weeds.
If you’re certain that the manure is weed-seed-free, then no worries.
Otherwise, you can greatly reduce this risk by thoroughly composting manure before you apply it to your garden. Or you can simply purchase manure that has already been composted. The composting process will destroy the weed seeds.
Manures often contain a fair amount of soluble salt – often as much as 5% to 10% of the dry weight of the manure.
This isn’t usually a problem, as rainfall and irrigation will normally leach the salts out of your soil.
But if your soil drains poorly, or you already know that you have a problem with salinity in your soil, you might want to be cautious about using manure.
Repeated applications of large quantities of manure can sometimes cause a deficiency of zinc. This is more likely to happen with sandy soils.
A potential zinc deficiency isn’t a reason to avoid using manure, but it is something to be aware of and monitor with soil tests.
It's important to remember that we’re only talking about using manure from herbivores – non meat-eating critters.
NEVER use manure from dogs, cats, pigs – or humans. These types of manures can potentially infect humans with a number of disease pathogens and parasites.
Cow manure fertilizer, chicken manure fertilizer and horse manure fertilizer are some of the most commonly used manures.
I’ve also used turkey manure fertilizer with great success (I bought it composted and bagged).
The first rule about using manure fertilizer is to NEVER apply fresh manure to a garden that has already been planted. Rather, incorporate fresh manure into your garden soil a few months before planting.
There are several reasons for this:
It’s quite possible for fresh manure to contain dangerous pathogens such as salmonella and e. coli. If you apply fresh manure to your growing garden, you run the risk of some of your produce becoming contaminated with these pathogens.
Once the manure has been incorporated into the soil, any pathogens in the manure will eventually die out, posing no risk whatsoever. Composting manure before using it will also eliminate this risk – but the manure must be composted thoroughly and completely.
Fresh manure contains nitrogen in a volatile form such as ammonia, which will be likely to burn your plants or inhibit seed germination. Aging or composting the manure will eliminate this risk.
Uncertainty About Fertility Levels...
Unlike labeled fertilizer blends, you won’t know exactly what you’re getting with manure. So how much to apply to your garden will be guesswork, at least to a certain degree.
One way around this is to buy packaged, composted manure. Packaged manure compost is usually labeled for the N-P-K and trace nutrients, so you’ll be able to calculate how much to use as easily as with any synthetic blend.
This type of manure compost is much more expensive than buying bulk, fresh manure, but the pricing is still usually more-or-less competitive with synthetic fertilizers. (See some examples below.)
Manure is a slow-release fertilizer. It takes time for the nutrients in manure to become available to your garden plants.
As the manure decomposes, the nitrogen and other elements are converted into a form that is useable for plants.
In fact, some of the nutrients in manure become available in plant-friendly form over a period of years.
Just to be clear, composted manure, like the products above or that you compost yourself, requires no waiting time. You can incorporate composted manure into your soil at the time of planting.
But if you incorporate fresh manure into your garden soil, the minimum wait time before planting is 2 months. Longer is better.
When adding fresh manure to your garden soil, work it into the top several inches of your soil. Never leave it lying on top of the soil - always work it in.
Manure can lose much of its nitrogen through exposure to the air.
As long as you have knowledge of how to use it safely, using manure as fertilizer can provide a wonderful boost to your garden.
And if you want to grow your garden using organic standards, manure fertilizer will likely be a mainstay of your fertilization program.
Manure is, after all, Mother Nature’s own fertilizer.