Organic: A real growth industry!:
It is one of organic farming's biggest criteria that no artificial fertilisers
should be used on the crops. So how do they encourage growth?
There are many natural alternatives to chemicals, and in general a combination
of these alternatives is used. Foremost, the ground is kept fertile by crop rotation
- some plants can replace nutrients and there is always time allowed for a field
to remain fallow - no crop is grown, but perhaps organically-raised cattle graze
on clover or grass ley. At the end of the season, the remaining ley is ploughed
back into the soil to keep its quality high. (This is also helped by animal by-products,
which in turn encourage earthworms.)
However, many farmers use compost on a large scale. Any left-over matter is heaped
together to create an ideal breeding-ground for helpful microbes and fungi, while
essential nutrients remain intact. This is then spread on the fields so that crops
profit from these beneficial organisms. Some nematodes found in compost, for instance,
feed on harmful bacteria and convert them into nitrogen-rich material from which
the plants can feed.
Compost should not be confused with mulch, another useful tool in the organic
farmer's armoury. Mulches (such as leaves or hay) are spread directly on the soil
to decompose there. They provide no nutrients but do add minerals to the soil;
however, their main purpose is in maintenance of the soil-surface microcosm. Mulches
can control soil temperature and evaporation rates, which are critical to efficient
growing, and also inhibit weeds. It also provides ideal conditions for earthworms,
which aerate and help fertilise the soil. (Some farmers rate the quality of soil
by counting the number of worms in a given area.)
One of the most impressive production methods is the concept of companion planting.
For instance, beans and potatoes are highly complementary and will often be grown
side by side. Each replaces some of the nutrients used up by the other. This is
merely an extension of the organic outlook: the farmers work in harmony with the
earth, so it's philosophically quite natural to have the crops working in harmony
with each other!
Related Links:
Cornell Composting. Cornell University's excellent compost resource, full
of science, tips and miscellany. The section on weird and unusual composting is
great fun.
Organic Growing.
A good guide to growing organic things, with particular emphasis on crop rotation
and complementary planting. One of the best resources of its kind.
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