published: September 23rd, 2008
Improve Garden Soil with Cover Crops
It is important to add organic matter to your soil every
year - whether you’re using chemical fertilizers or
gardening organically. Healthy soil is alive, actually
teaming with earthworms and micro-organisms by the millions
that have each got particular functions in making the soil
fertile. If your garden soil is going to continue to
produce for you, it needs to be fed plenty of organic
material.
Soil life eats and decomposes organic matter, which causes
minerals to be released in a form that plant roots can
absorb. In addition to this fertilizing effect, all the
organic waste helps the texture of the soil - loosening
hard-packed clay or binding loose, sandy soil. Humus gives
the soil its necessary sponge-like texture that allows air
circulation and moisture retention.
For these beneficial processes to take place, the life in
soil needs fresh fuel, (organic matter). Without this
food, earthworms leave and microbes die, causing nutrients
to get locked away by soil particles, unavailable to the
plants. Insect pests and diseases then attack the under-
nourished and vulnerable plants. It doesn’t help to pour
on the chemical fertilizers; they don’t contribute to a
flourishing soil life or spongy soil texture.
This is a simplification of a very complex natural process
of soil chemistry that justifies in-depth study in its own.
But the intention here is to give a basic idea of the
absolute necessity of a generous annual addition of organic
matter to all continuously used garden soil. Now, here are
some suggestions about how to feed the soil.
Haul in compost, buying it in packaged form or by the yard
from nurseries. Processors in your area (cider mills,
canneries, etc.) often have organic material for the
taking. Farms nearby might welcome removal of animal
manures: horse, cattle, chicken, rabbit are all good. Of
course, chop garden residues and weeds into the soil after
the crop is finished. Also chop in the hay or straw that
was used as mulch. Gather leaves and lawn clippings and
dig them in.
Here’s the quickest, least hassle method for taking just
about any stretch of soil and turning it into excellent
loam. Grow a cover-crop, or green manure, and simply till
it in. This practice, when done over time, actually
replenishes the top-soil instead of removing it with
harvested crops. This is a particular benefit for gardeners
who are growing food in the same location over a period of
years.
Notes on using green manures:
1) You can grow green manures in a rotation (an early
green manure followed by a late-season planting of produce,
or a late cover-crop following an early summer harvest like
lettuce and peas) so that even if you have a small garden
you will have a harvest crop as well as a cover-crop every
year.
2) Using green manures can be done by any gardener with or
without powered equipment. However, a roto-tiller is the
easiest method. If necessary, you can rent one.
Here are the most common kinds of cover-crops for home
use.
A) Buckwheat: in addition to growing well even in poor
soil, it chokes out weeds. Sow buckwheat in summer, after
harvesting peas, etc.
B) Ryegrass: this grows rapidly and is very hardy, adding
a good amount of bulk. Best to choose annual varieties.
Ryegrass is a good crop for late-summer since it dies back
for easy tilling in spring.
C) Legumes (alfalfa, peas, vetch, soybeans, etc.): these
will “fix” nitrogen from the air if you use “inoculated”
seeds, attracting the right micro-organisms. Notice that
some legumes are vegetables; giving both food and green
manure from the same crop.
In addition to its benefits to soil, there are many good
reasons to grow green manure. They help with weed control,
bee attraction, and provide a beautiful green cover that
keeps the garden looking nice right up to the time snow
flies.
Valerie Palmer, writer and master gardener, contributes to
TLC Gardening,
offering valuable free information to enhance your gardening
experience. Also visit Full Storage or FB Home
to find more articles by Valerie Palmer.