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HOW
TO USE COMPOST
This
is the easy part. You just spread it
around!
For
any application needing fine particles, you will want to sift the compost. This can be done with any type of screen
material fixed to a frame. They come in
various shapes and sizes, from 14” metal rings with mesh bases to litter box
like plastic pans with interchangeable screens of different gauges. Most commercial sifters use a ½ or ¼” mesh.
My
sieve/sifter is the lid of a galvanized garbage bin through which I laboriously
hammered concentric rings of holes. The
holes are not very big so I get a very fine product.
The
scientists offer some caveats, and warn that you should only use mature or
stable compost. My
biggest gripe with the United States is that as soon as there is the slightest
chance that something may, under certain circumstances, be dangerous to a very
small population, a law is passed to make it illegal. No one is permitted to take even the smallest calculated
risk. With
that off my chest, let me say that there may be some negative effects when
using immature compost. The best known
of these is that immature compost can temporarily rob the soil of
nitrogen. That is why you should wait a
few weeks between amending the soil with young compost, and planting. In those few weeks, the balance changes and
microbes begin to release nitrogen.
Immature
compost is not good for seedlings because it may contain competitive seeds, it
may still be absorbing nitrogen and it may still contain phytotoxic (poisonous
to plants) elements such as volatile organic acids and salts. For
these reasons commercially prepared compost is carefully regulated as to when
it may be used in nurseries.
On
the other hand, immature compost applied as a mulch provides all the benefits
of mulch – temperature control, moisture control, – and seems to have a mild
herbicidal effect, thereby adding to the other benefit of mulch, namely, weed
control.
Suggested uses for varying degrees of maturity in
compost are:
Very mature compost is a well-cured compost, which
has completed the rapid decomposition process, the
original materials are unrecognisable and there is no odor. When screened (sifted) this is perfect for
seeds and seedlings. Many resources suggest that it can also be used as part of
a soil and peat-based mix for container plants. I have mentioned my aversion to peat, and I would use perlite or
similar to lighten the mix.
It is very good for top dressing a lawn or
dense planting such as groundcover, where you can scatter the very fine product
on top of the plants and then shake them to drop it down to soil level.
Mature compost has undergone some curing. It is unlikely
to produce odors, and has minimal impact on nitrogen in the soil. It
can be used when planting trees, shrubs, perennials, and to prepare a bed for
annuals. Good also for general field use (pastures, hay), if you are into
farming, or for vineyards. This is the
compost to use for you vegetables.
Immature compost may
produce odors and still contains some recognizable materials such as stalks and
twigs, large leaves. Its
main uses are to amend fallow soil, and to add organic matter to depleted soils,
with the assumption that the area will be left unplanted long enough for the
curing process to complete. Immature compost is also a very good start for the
next compost pile. As
mentioned above, you can successfully use it as a mulch. My gardening guru in
Rome used to say: “You don’t have to dig it in: the worms will take it
down.” And they do.
A
word here about mulch. There is no one
thing that is mulch, although there are many materials that can be used as
mulch. Straw, woodchips, plastic sheeting,
shredded newspapers are just straw, woodchips, plastic sheeting and shredded
newspaper until you decide to put them to good use as a great way to preserve
moisture and soil structure, while keeping down weeds.
Compost tea.
Compost
tea is easily made by soaking or steeping compost in water. The resulting
compost tea is used for either a foliar application (sprayed on the leaves) or
applied to the soil. Many
websites and books insist that it needs to be artificially aerated in order to
be effective. In fact there is a minor
industry supplying all kinds of
equipment with which to aerate the tea.
However,
the Co-operative Extensions of both Maine and Washington maintain that
additional aeration is not necessary.
Compost
tea is a great way to make a little compost go a long way, and the foliar
application in particular, has good anecdotal and research-based evidence of
disease fighting qualities, including against the dreaded late blight.
On
the purely anecdotal level, in 2009 when upstate New York had serious late
blight, I surveyed our Garden Club members.
In all but three cases, tomatoes had been wiped out, more or less
overnight. The three exceptions did not escape completely, but
our compost-fed tomatoes survived for the entire season, producing until the
end, albeit in limited quantities.
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