What is hydroponics?

Hydroponics is a technology for growing plants in nutrient solutions (water containing fertilizers) with or without the use of an artificial medium (sand, gravel, vermiculite, rockwool, perlite, peatmoss. coir, or sawdust) to provide mechanical support.

Liquid hydroponic systems have no other supporting medium for the plant roots: aggregate systems have a solid medium of support. Hydroponic systems are further categorized as open (i.e. once the nutrient solution is delivered to the plant roots, it is not reused) or closed (i.e. surplus solution is recovered, replenished, and recycled).

Hydroponic growing (as opposed to soil growing) allows you to control the nutrient levels for your plants directly. Because of the higher control over nutrients, hydroponically grown plants generally have a much higher yield than similar plants grown in soil.

Hydroponics growing

A plant gets its food source by turning Co2, light and water (or hydrogen) into carbohydrates through a process called photosynthesis. With hydroponics growing, plants are grown without soil so they must get their nutrients from the nutrient solutions added to water. The absence of soil in growing means that hydroponics systems must have some way of supporting the plants while still allowing the bare root system maximum exposure to the nutrient solution. Often a “growing medium” is used for support and to aid in moisture and nutrient retention in hydroponics growing. Because they lack media to store water and nutrients, water culture systems need a continuous flow of nutrients to prevent drying out the plant roots.

Plants need an energy source in order to grow. With hydroponics growing this energy may come from natural light, which has the full spectrum of color or through the use of different types of artificial lighting (grow lights), which can be selected for specific plant varieties and optimum plant growth characteristics.

Hydroponics Vs Soil

With hydroponics currently at new heights in the gardening world, the question facing gardeners today is Hydroponics or Soil? This question is also becoming an age old debate of battling sides fighting to prove the other wrong. I won’t be taking a stance on the issue. Instead I’ll explain the key differences among hydroponic and soil gardening as well as advantages and disadvantages for both techniques.

The fundamental difference between hydroponic and soil gardening is the growing medium. In a soil-based garden, that medium is the soil itself. In hydroponics, the medium is a nutrient-enriched liquid solution. Each method has advantages and disadvantages. For either to produce healthy plants, the basic nutrients must be made available to the plant roots.

Hydroponics commercially efficient and time-saving, is not practical for the amateur. There are too many risky factors involved- most importantly, it is easy to have an unbalanced nutrient solution, which will stunt the growth of the plants. Our nutrient solution lacked enough of the important nutrients nitrogen and potassium, as we could tell by the appearance of our plants. The nitrogen deficiency caused the plants to have abnormally light-colored leaves and stunted growth. The fact that our hydroponics plants did not grow very much is explained here. 

The potassium deficiency caused our plants to have stunted growth and slightly withered leaves. Although the hydroponics clearly fared worse than the soil plants, the soil plants still were not productive in this experiment. This was probably caused by the fact that the fluorescent gro-light was not as close to the plants as to simulate sunlight, and therefore the plants did not grow as fast as we had hoped. However, the soil plants did grow steadily if slowly, and were more healthy than the hydroponics plants in the end.

Advantage of Hydroponics

An advantage hydroponics gardening compared to soil gardening is the control the gardener has over the quantity and content of the nutrients. The solutions may be tailored to specific plant needs and plants needn't compete with other plants or weeds for nutrients as happens in soil gardening. The risk of damage or disease from soil-borne pests is greatly reduced, due to the lessened exposure to these pests.

Advantage of Soil

Soil has the advantage of the organic factor. Although all nutrients need to be in an inert form for roots to access and process, the nutrients may be in organic form when added to soil. In hydroponics, the nutrients must already be inert and immediately soluble, and so are synthetic. The organic nature of soil gardening encourages the development of ecosystems that include bacteria, fungi, worms, insects and birds, all of which contribute to the natural renewal of nutrients in soil. The soil gardener need only assist in nutrient renewal, rather than control it. No such sustaining ecosystem exists within hydroponic gardening methods.

Reference: http://www.ehow.com/
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