Formulas are defined for a given crop growing under different
conditions. For example, elements are specified for the nutrient
reservoir, while a separate specification is made for the nutrients in
the "root environment" if growing media is used, particularly
rockwool. The root environment usually has higher concentrations
of elements since minerals will accumulate in rockwool. To test
the concentration within the media, the grower will squeeze some
nutrient out of a sample of the media, do a basic conductivity and
pH test, and sometimes send the sample to a lab for analysis. If the
concentration of elements in the media rises above the
recommended limits, the grower will have to adjust the
formulation of the nutrient in the reservoir or run a rinse through
the media to lower the nutrient concentration within the root zone.
Another formula may be defined for non-recirculating nutrient,
also called "run-to-waste," where nutrient is sent from the reservoir
on a one-way trip through rockwool onto the ground. This method
is falling into disfavor due to the pollution caused by the nutrient
run-off and discarded rockwool.
HYDROPONIC PRODUCE AND HEALTH
In 1994 a test was commissioned by an investment group to
determine the vitamin and mineral content of hydroponically
grown crops in comparison to soil grown crops, both organic and
nonorganic. Plant Research Technologies Laboratory in San Jose,
California, analyzed tomatoes and sweet peppers; those
hydroponically grown used General Hydroponics' "Flora" nutrients. The hydroponic produce showed a significant increase in
vitamins and minerals beneficial to human health over the soilgrown
produce. This data indicates the importance of a calibrated
nutrient solution. The crops had been grown following the Dutch
recommendation for hydroponic tomatoes and sweet peppers, and
not only were they of higher nutritional value, the flavor was
reported to be outstanding.
The hydroponic crops were further analyzed to search for
chemicals on the EPA’s "priority pollutant list", of which, none
were found. American agribusiness is beginning to apply hydroponics on a
significant scale. Large corporate facilities are showing profits and
generating high crop yields with consistent quality at facilities in
Colorado, Utah and Mexico. These installations mark an important
point for hydroponic farming in the United Stares. If the
investments prove profitable over the long term, then steady
growth is going to continue, slowly replacing many field-grown
crops in the marketplace. The British have been applying
hydroponic farming to meet consumer needs for decades. Farming
cooperatives grow tomatoes, cucumbers and salad greens on a very
large scale.
Van Heinegen Bros. produces three pounds of hydroponically
grown tomatoes per year for every man, woman and child in the
British lsles. In support of these enterprises, the British
government runs a research facility, which investigates improved
hydroponic methods, disease and pest control and new plant
varieties. The cooperation between government and farmers has
led to improved crop production, quality and profits.
Although hydroponically grown produce, while usually free of
pesticide and other chemical hazards, does not generally meet the
rather narrow definitions of "organic", it can offer superior flavor,
nutrition, appearance, freshness and she1flife. Many small
hydroponic growers are recognizing these market trends and
cashing in on the huge demand for higher quality produce. Small
growers find that gourmet restaurants and local markets are
delighted to have access to superior quality produce, whether
organically or hydroponically grown.
Since "organic" is pretty much out of the question, an increasing
number of hydroponic growers are promoting their produce as "pesticide-free." This gives the consumer the reassurance that their
fruits and vegetables have been grown following the most
important principal of "organically” grown produce.
One consequence of this dichotomy is that the term "organic
agriculture" is declining in favor of the term "sustainable
agriculture", which applies to both organic and hydroponic
cultivation. Though many organic growers look down on
hydroponic technology, the superior quality and freshness of
locally grown hydroponic produce is in fact gaining market
acceptance. A new niche is developing for small hydroponic
growers, family farms, and even urban farms in areas that have
traditionally been served by large corporate farms far away.
The simple truth is that top quality organically raised produce can
only be grown under fairly ideal conditions and only seasonally in
most parts of the United States. This results in produce that is
expensive and frequency unavailable or shipped from afar, causing
quality to suffer.
In the "organic” model, good soil is enriched with compost, blood
meal, bone meal, manures and a host of other natural amendments.
These components break down slowly in the soil at a rate in
harmony with the plants' growth; a microbiological process is
required to make the nutrients available to the plants. These
microbes include many organisms that are all in a symbiotic
embrace with the environment and the plants. When done skillfully
in the right environment with the right crop, this is nature and
farming at its finest. But it differs sharply from the hydroponic
model, where microorganisms are unnecessary for the plants to
absorb the prepared nutrients. The nutrient absorption rate of a
hydroponically grown plant is generally much faster than that of a
soil grown plant, since in hydroponics, nutrients are instantly
soluble and available, as is essential oxygen.
Hydroponic plants are usually grown in a relatively sterile
environment, and often with precise controls, from artificial
lighting to extend growing seasons to exotic computer systems that
enable the grower to actually tailor the environment to the crop
wherein hydroponics becomes just one part of the entire system. In
this type of setup, labor is reduced, yet plant growth rates, yields
and quality increase.
Many attempts have been made to create the perfect organichydroponic
nutrient, but so far nothing matches the purified
mineral salts used in formulating hydroponic nutrient solutions.
We note that the European Economic Community (EEC) has
established the category of "mineral organic" for foods grown with
the required mineral nutrients to supplement an organic base of
nitrogen. We previously touched on the fact that United States
agricultural regulations are currently set and applied at the state
level but practically all states prohibit the use of refined ingredients
to cultivate “organic" crops; only mined minerals can be used.
Surprisingly, this precludes organic growers from using pharmaceutical or food grade ingredients to formulate fertilizers.
This could be a safety risk, but at least mined minerals will break
down in the soil.
Hydroponic growers, on the other hand, must use refined minerals
because mined minerals dissolve poorly in solutions. As a
consequence, it is not currently practical to formulate a top-quality "organic" fertilizer, which will work well for hydroponic crop
production, and meet U.S. standards. The Flora nutrients
developed at General Hydroponics, for example, currently meet the
EEC standards for the mineral component of the "mineral-organic" category, but cannot be used in the United States to grow certified "organic" produce.
A review of the standards for defining "organic" will soon be
completed by federal regulators in the U.S. Department of
Agriculture. There is some possibility that the USDA way
eventually consider the European standards, opening the door for
organic growers to use purified mineral nutrients and hydroponic
growers to cultivate organically certified produce. It is not
surprising that European regulations favor policies that promote
the cultivation of produce with superior quality and flavor.
Generally European consumers are accustomed to higher quality
foods and will not purchase flavorless produce. The myth that only
certified organically grown produce is of good quality, nutrition
and flavor has been clearly dispelled by the many successes of
hydroponic producers worldwide, but remains predominant in
public perception. This trend will most likely continue; the only
question is whether the United States will be a leader, or a
follower.
Lawrence Brooke is the president and founder of Sebastopol,
California based General Hydroponics, Inc.
Author's note: I’ve tried to describe a few of the problems
hydroponic growers face when trying to compete with "organic" produce. I don't wish to leave readers with the impression that
there's anything wrong with organic, or that hydroponic produce is
always better. It can go either way depending upon the skill and
ethics of the farmer.
The main issue is for growers and consumers to understand that "organic" is a matter of definitions. Sometimes the organic produce
is the best tasting and most nutritious available in the marketplace;
other times the hydroponic produce is better. In the final analysis,
organic farming has a low environmental impact on the Earth, and
this is an important point from a philosophical view. Until
hydroponic growers can find a way to recycle used water, media
and nutrients, the hydroponic method will not be equal to "organic" in these terms. On the other hand, if a consumer is
comparing the flavor and nutrition quality of a crop, both
hydroponic and organic methods are excellent.