by Monica Mansfield
Manure is known to be an effective
fertilizer in the garden, but there is
considerable science behind effective
application. Monica Mansfield rolled up
her sleeves to research proper application
rates, techniques, and safety precautions.
M
anure has been used to fertilize farms and gardens
for centuries. It is a prime source of slow release
nutrients and adds organic matter to the soil. As long
as you use the proper methods, you can safely take
advantage of its many benefits.
Benefits and Drawbacks of Manure
Adding manure is an excellent way to improve your soil.
It promotes the growth of soil life such as earthworms and
beneficial microbes, which in turn creates better tilth and
soil structure. When you amend sandy soils with it, you’ll
increase your soil’s water-holding capacity. Amending clay
soils will increase drainage. As the soil life works, the rich
humus left behind will create dark, spongy topsoil.
The soil life will make a majority of the nutrients available the
first year, with the rest feeding the plants over the next one or
two years. As time goes on, and nutrients build up in the soil,
you will need to add manure on a less regular basis.
In fact, you need to be careful not to add too much manure to
your garden. If you do, you may experience excessive vegetative
growth, salt build up, nutrient runoff, and nitrate leaching.
Proper application rates are essential when using manure.
Application techniques are also important, especially
when using fresh manure. Incorrect methods can spread
E. coli, Salmonella, Campylobacter bacteria, and Giardia
or Cryptosporidium protozoa.
Types of Manure to Use
Typical manures used in the garden are from poultry, cows,
sheep, and horses. Never use manure from cats, dogs, or pigs
as they are more likely to spread parasites to humans.
Manures may or may not have bedding mixed in. The more
bedding mixed in, the more diluted the nutrients are. You can
also choose fresh or composted manure.
It’s important not to use manures that have been contaminated
by herbicides. If broadleaf herbicides have been used on
lawns, pastures, or hay that animals have eaten, their residues
can pass through their digestive system to the manure and
remain even after being composted. The herbicides will break
down eventually, but they can cause damage in the meantime.
If you use contaminated manure or compost, your crops will
experience poor germination rates, seedlings will die, and
vegetation will be twisted and malformed.
Maximum Yield
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