Agriculture Reference
In-Depth Information
The various fans and promoters of soil biology, from earthworms to fungus, tell us
that a bio-active soil will break down toxic residues, increase humus, and the
beneficial soil organisms will make minerals and nutrients available to the plant.
The question that is not asked is “what if the needed minerals are not to be found
in the soil?”
The newer high-tech solutions, such as hydroponics, or even newer, aeroponics,
rate a careful examination. Can we count on them to rescue agriculture? Not if the
goal is to feed the world's people and animals. They are fine for growing some
pretty tomatoes to sell at the supermarket, or some nice lettuce in the basement,
but these "new and modern" systems have a number of basic problems, some of
them insurmountable if the goals are sustainability and nutrient-dense food. The
most obvious failing is that they are energy-hungry.They use pumps and fans and
often lights. In the interests of self-sufficiency, where is that energy to come from?
If the power goes out is one going to pedal a bicycle generator to keep the pumps
and fans going? In addition to being energy-hungry, both hydroponics and
aeroponics require special containers, growing solutions, training and handling.
They are not automatic.
There are other not so obvious problems with hydroponics.Any time one has a
liquid-based growing solution they need water-soluble fertilizers, and these must
be pure. One does not put compost in the hydroponic trays. This makes all natural
organic hydroponics pretty difficult.Another drawback is that only certain crops
are suitable, mostly the ones you have seen in the stores so far: lettuce, tomatoes,
peppers, and some herbs. One will not raise a field of potatoes, cassava, or
turnips hydroponically, nor thousands of acres of grains and legumes. One will not
grow hay to feed animals hydroponically or aeroponically.
The most serious downside to these systems, though, is the lack of nutritional
completeness in the produce. Designer vegetables grown in nutrient solutions are
grown for looks, not nutrition. No one has yet shown that a nutritionally complete
diet can be grown in this artificial manner.
Mention should be made of the ultimate closed-environment theory of the day (or
decade), the all-in-one fish pond and hydroponic garden.As you may know, the
idea is that one raises fish in a pond, then uses the fish water to irrigate the
hydroponic troughs. The nutrients from the fish water are used as fertilizer for the
plants. The water comes out "clean" at the other end and is recycled back to the
fish pond. Various theories suggest what the fish eat, but the grower gets to eat
the fish and the vegetables. The theory sounds good, but all the designs seem to
require glass or plastic domes. We will not feed ourselves and heal our polluted
environment by creating isolated bubbles in the landscape.
The high-tech systems above are things to learn from and we will and have
gained knowledge from them. One valuable contribution is that we know more
about what mineral nutrients are absolutely essential for plant growth. These
