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With the first successful application of
hydroponics techniques in the 1930s the stage was
set for a paradigm shift in crop production from
conventional geoponics or cultivation in soil to
hydroponics or soil less cultivation. The first
crops to be commercially harvested with hydroponics
included tomatoes and peppers, but the techniques
were soon successfully extended to other crops such
as lettuce, cucumbers and others. It was not long
before hydroponics techniques were successfully
adapted even to cut flowers production; in fact any
plant can today be grown hyrdroponically.
Commercial Systems Overview
Commercial hydroponics systems can be
classified into bare root systems comprising
nutrient
film technique (NFT), deep flow and aeroponics
systems and substrate systems.
Bare root systems do not use media to anchor the
plant roots; the roots are left bare while in
substrate systems plant roots are anchored in media
such as perlite, vermiculite, sawdust, peat etc.
Hydroponics is basically all about growing plants in
a controlled environment and this is best provided
outdoors in greenhouses that can incorporate several
means to monitor, regulate and control the
environment inside them. For instance, the air
entering the greenhouse can be filtered to exclude
entry to pests and parasites that can harm plant
growth. Such means help provide optimal conditions
for plant growth both in and out of season. In fact,
hydroponics allows cultivation throughout the year
which makes for year round availability of
hydroponically grown produce at all major
supermarkets across North America. Valued at 2.4
billion dollars the hydroponic greenhouse vegetable
industry has a growth rate of 10 percent per year
and accounts for nearly 95 percent of the greenhouse
vegetables produced in North America.
Hydroponics Advantages
The extension of the growing season is not the
only advantage contributing to the growing
popularity of hydroponics production with both
growers and consumers. There are several additional
advantages as well including nutritious, healthy and
clean produce, improved and consistent vegetable
quality and elimination of the use of pesticides and
herbicides. Pesticides and other chemicals used in
conventional agriculture have an adverse
environmental impact; the run off from these
chemicals contaminate groundwater supplies.
Commercial
hydroponics systems eliminate these toxic
chemicals and contribute substantially to keeping
the groundwater free from contamination.
Yields
Commercial hydroponics systems have proved more
productive than conventional systems of agriculture
not only in the laboratory but even in actual
practice. Most commercial hydroponics greenhouse
facilities are built large to take advantage of
economies of scale; typically these cover areas more
than 10 acres while smaller ones measure around two
acres. In the research greenhouse, yields with
hydroponics techniques have averaged around 20 to
25% higher than in conventional soil cultivation. In
actual commercial practice, however, over a number
of years, the yield of hydroponically grown tomatoes
can be more than double that of soil based systems
due to the reduced turnover time between crops,
better nutrition and crop management. Additionally
commercial hydroponics growing techniques are also
less demanding of chemicals for root zone
sterilization and control of pests, weeds etc. The
dramatic increase in yields with hydroponics is best
illustrated if we consider the actual production
figures of soil grown and hydroponically grown
produce. Field grown tomatoes average yields ranging
between 40,000 to 60, 000 pounds per acre; on the
other hand top growing hydroponics facilities in the
US and Canada report average yields of more than
650,000 pounds of tomatoes per acre. Additionally,
given the fact that only 10 years ago top
hydroponics producers were producing around 400,000
pounds per acre, the increase in yields with
improvements in growing practices has been truly
phenomenal. Similar production figures can be quoted
for other agricultural produce like cucumbers with
10,000 pounds per acre for field production and
200,000 per acre for hydroponic greenhouse yields.
Hydroponics lettuce and pepper yields too average
around four times the corresponding yields of
agricultural production. Global Trends
Given the number of advantages of hydroponics it
is not surprising that hydroponics techniques are
increasingly finding favor for commercial food
production in many countries all over the world.
According to recent estimates countries having
substantial commercial hydroponics production
include Israel – 30,000 acres, Holland 10,000 acres,
England 4,200 acres and Australia and New Zealand
around 8,000 acres between them. The fastest growing
area for commercial vegetable greenhouses is Mexico.
There are several reasons for this including free
trade and favorable winter conditions that attract
vegetable growers in large numbers. Mexico has
summers that are considered hot in the summer, but
with greenhouses located at the right altitudes
vegetables can be grown in the hot summers as well
as the cold winters. Though much of the produce
comes from low tech plastic houses, many of these
greenhouses use hydroponics technology, which
indicates the growing popularity of hydroponics in
commercial food production.
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