The technologies of hydroponics allow for the growing of plants without the use of soil. Plants are anchored in an inert growing medium within a contained system. Nutrient-enriched water, held in a reservoir in the system, is forced over and around the plant roots either at specific intervals or in a continuous stream.
The technology behind hydroponics is based on the biological approach that plants do not require soil to grow, but rather the nutrients found within the soil, along with water and light. By adding water soluble nutrients directly to the water and giving plant roots direct access to the nutrient-rich solution, soil is no longer required.
The soilless approach allows for agriculture to thrive even in regions in which the quality of soil prohibits agricultural industry. Hydroponic systems may operate indoors as well, on a small or large scale, so the technology is well-suited to areas in which space is at a premium and/or large swatches of soil are unavailable.
The principle behind hydroponics lies in washing plant roots with nutrient-rich water. Hydroponic systems vary and the notable difference is how that solution is delivered to the root systems. Different systems include ebb and flow, the drip system and the nutrient film technique.
The ebb and flow system floods the roots and the solution then slowly flows back into the reservoir. The drip system, sometimes referred to as the Dutch bucket, pumps the solution through a tube onto the base of the plant. The solution then drips downward onto the roots and then returns to the reservoir. The drip may be continuous or at intervals. The nutrient film technique pushes solution through a tube in a continuous flow. The plants' roots are dangling within this tube. The solution in this method must also be well oxygenated and move quickly to avoid "suffocating" the plant roots.
Any type of hydroponic system recycles the nutrient-rich solution. Because of this, hydroponics uses less water than soil gardening or agriculture. The solution within a system is renewed at regular intervals to prevent depletion of nutrients. This is akin to adding fertilizer to garden soil.
Hydroponics may be believed by some to be an artificial means of growing plants, or inorganic and therefore not an environmentally friendly form of agriculture. Hydroponic technology uses a contained system, recycled water and if indoors, artificial lighting. The plants, however, are grown organically. The nutrients used are of the same chemical makeup as those found in soil that plants take up through their root systems. Hydroponic systems recycle water and the use of these systems alleviates such issues as soil depletion and groundwater contamination through the use of synthetic pesticides, herbicides and fertilizers.