The word “hydroponics” is thought to have been derived from the Latin
“water working.” Water is the basis for hydroponics. Stated plainly,
hydroponics is the growth of plants without soil. History Though often thought
of as modern and experimental, hydroponics is an ancient practice. Though it
wasn’t known at the time, the Hanging Gardens of Babylon were hydroponic. Less
famous, the Aztecs’ Raft Gardens also were hydroponic. In the year 1699,
scientist John Woodward presented a paper before the Royal Society of England.
His paper concerned an experiment that he had performed involving plants grown
in polluted river water versus plants grown in rainwater. This paper attacked
the problem of whether or not the health of plants was determined by the
dissolved solids of the water from which they were grown. In the years
1851-1855, Jean Baptiste Boussingault, French chemist, performed an experiment
of plant growth in quartz and sand cultures with no soil. He used only water and
chemical nutrients. In Germany in 1860, botanist Julius von Sachs published the
first noted nutrient solution formula. In 1865, Wilhelm Knop, a German
agricultural chemist, formed another nutrient solution. In the years 1900-1920,
scientists extended the established number of elements that made a successful
nutrient solution from six to ten. Hydroponic experiments were becoming more
successful with these new elements. In the 1920s William F. Gericke termed this
method “hydroponics.” Researchers began to realize how this method of growth
without soil could be useful. In the 1940s, mainly during World War II, the
United States armed forces executed hydroponic operations in the South Pacific
to cut down the cost of transportation of fresh fruits and vegetables to the
troops stationed on the islands. In the 1970s, Dr. Alan Cooper developed the
system called “Nutrient Film Technique” (defined on page 6). Today the use
of hydroponics is becoming more widespread. The Hanging Gardens of Babylon were
a series of solariums filled with plants. Investigations have concluded that an
intricate tunnel and pulley system was used to bring the water from the ground
to the top platform. It is a possibility that the water used was waste from
human inhabitants. This would actually make the gardens hydroponic because
nutrients were added to the plants. The Aztec Floating Gardens or rafts were
called “chinampas.” They were locates on Lake Tenochtitlan, in Mexico. The
rafts were constructed of rushes and reeds that were bound together with roots.
The Aztecs then took mud from the bottom of the lake and collected it on the top
of the raft. Then vegetables, flowers, and even trees were grown on the rafts.
Some of the roots sprouted down into the lake. The nutrients in the mud and in
the lake helped to produce lush gardens. Pros and Cons Of recent years, the
method of hydroponics has become more widely used to grow healthy plants,
vegetables, fruits, and herbs indoors. Plants can be grown out of soil, their
natural way of growth, because the physiological needs of plants can be met in
an environment void of soil. Nutrition in hydroponics is provided by a liquid
solution made of water and water soluble mineral elements. The plant’s roots
are supported in an “inert medium.” This inert medium will be discusses
later in this report. Aside from the fact that plants do not physiologically
need soil, there are many other reasons why the use of hydroponics is becoming
more popular. One of these reasons is that hydroponically grown vegetables claim
dramatic increases in vitamin and mineral content as opposed to geoponic (grown
without the use of soil) vegetables. There are also many advantages of
hydroponics related to the caretaking and ease of gardening. This is a chart to
demonstrate some of these reasons: Geoponic Growth Hydroponic Growth Suitable
soil must be found and present. Suitable soil is not necessary. More time and
space is necessary. Space requirements and growth time are reduced. Plants must
be planted; fields must be cultivated, etc. The heavy work is reduced. The plot
must be weeded. There are no weed problems. Crops must be rotated (in commercial
growth). There is no crop rotation. Transplant shock can occur. Little if any
transplant shock occurs. Frequent watering of the plants is necessary. Plants do
not need to be watered as often. There are also benefits of indoor growth versus
outdoor growth: Outdoor Growth Indoor Growth Limited plant growth Conditions and
plant types determined by the grower Too high/ low temperature Temperature
controlled Too much/ little sun Light controlled Too much/ little rain
Controlled water supply Bad weather No storms; no bad weather Still more
benefits of hydroponics are included in an environmental or nutritional
category. Geoponic Growth Hydroponic Growth Soil loses its nutritional value; it
is difficult to measure in terms of fertility Nutritional value of water is
easily measured; plants are always nourished Soil is home to many troublesome
creatures Conditions are sterile, hygienic environment Excess water is used
Water is conserved Disease and pest problems Disease and pests can be controlled
Pesticides contaminate plants Pesticide free Some nutrients are wasted Nutrient
solution can be recycled Soil can not be reused Growing mediums can be recycled
Much soil is necessary Little growing medium is necessary Spacious amounts of
arable land is used Non-arable land can be used Year round crop production uses
fossil fuels Fossil fuels are not used Not very pest resistant More pest
resistant Sometimes artificial ripening agents must be added to the produce
Plants are always vine-ripened Hydroponics, in a small scale, has been used
efficiently by farmers, on a commercial level, for years. These hydroponic
farmers have many advantages over farmers that farm using soil. Some of these
advantages have been summarized in the charts above. By using hydroponics. A
farmer is basically creating his own perfect nature. His time of growth, yield
of growth, and quality of products can be predicted and controlled while the
geoponic farmer has to deal with unforeseen events of nature. In addition,
hydroponic vegetables and fruits have been proven to be healthier than soil
grown. While the pros heavily outweigh the cons of hydroponics, there are some
disadvantages. Some of these are:  The cost of setting up a hydroponic
system can be high.  In a commercial environment, knowledge and skill
are needed to achieve maximum production  The benefits of helpful soil
life is lacking  The sharing of nutrient solutions can spread disease
and pests  There are some plant varieties that are not suitable for
hydroponic growth  While plants react quickly to good conditions, they
react just as quickly to bad conditions Growing Techniques The one main
condition of hydroponics that must remain stable is the water supply. There are
many techniques of bringing water to the plants. Nutrient Film Technique (NFT):
This is the traditional form of water distribution. The nutrients are supplied
to the roots by growtubes. The remainder of the solution that is not used is
pulled back to a reservoir by way of gravity. Drip or Micro-Irrigation: This
method has been used increasingly. A minimal amount of water is used, with the
plant receiving the full benefit. A submersed pump provides nutrients to feed
lines that constantly drip water over the plants and the roots. An additional
tube underneath receives the excess solution to be reused. Aeroponics: The roots
of the plants are hanging in an oxygen-rich nutrient solution. This allows for
easy inspection and pruning. Air pumps provide oxygen and other pumps spray the
roots with water. Deep Water Culture: This is another form of aeroponics. The
roots of a plant system are submerged in water. A ventilator keeps the roots
oxygenated. Flood and Drain: These systems resemble NFT systems. A submersed
pump connected to a timer systematically floods a plastic growing bin. The inert
medium and the roots are drenched, and then drained by way of gravity. Rockwool
(which will be discussed further below) is the most common medium used with the
Flood and Drain System. Passive Planters/ Hydroculture: This is the most common
method and will be used in the project. These systems do not need a water or air
pump, hence the name “passive.” Planters using this system use an
uncontaminated, permeable medium. A nutrient store in the base of the container
used for growth allows the plants to take the exact amount of water that they
need. Inert Growth Mediums In spite of the fact that hydroponically grown plants
do not use soil, something must still anchor them. There are many materials that
can be used as these mediums. The type of medium used depends on many factors,
including the size and type of plants, and the type of hydroponic system used.
This section will discuss a few of the main mediums. Heydite and Hydrocorn:
Heydite is porous shale that allows for free drainage and air space. Hydrocorn
is clay pellets. Both are easy to reuse and clean and they are both good for
continuous drip systems. They provide secure foundation for large plants.
Rockwool: Rockwool is made by melting basalt rock and chalk into lava, then
pulling it into fibrous cubes. It insulates well and provides a good
water/oxygen balance. Rockwool is used in continuous drip or flood and drain
systems. Most often Rockwool is only used one time. Perlite and Vermiculite:
Perlite is a light white material that is often used in soil. Vermiculite is a
flaky shiny substance that is often mixed with Perlite They do not provide
enough support for large plants. They are often used when plants are young or
seedlings. Some hydroponic systems do not require any medium at all and use some
other means of support.