Hydroponics is the practice of growing plants without soil. The chief advantage to this type of gardening is that plants grown hydroponically avoid soil-borne diseases and pests. Plants grown in such carefully controlled conditions also achieve faster and greater yields. Artificial light provides the energy hydroponic plants need just as sunlight does out in the field. Instead of taking up nutrients from soil, hydroponically-grown roots absorb essential elements dissolved in water.
Research continues to provide more information on what exactly helps plants live and thrive. In the spectrum of light, red and blue wavelengths benefit foliage best. Additionally, there are at least 16 nutrients necessary for plant growth. Of these, hydrogen, oxygen and carbon are non-minerals that are readily available in soil and must be supplied in solution for hydroponics systems. Mineral nutrients include the three most important: nitrogen, phosphorus and potassium. Secondary nutrients calcium, magnesium, sulfur and micronutrients like boron, copper and iron all make up important elements that roots usually take in from soil.
Roots in Specialized Fluid
Most water-based hydroponics systems are of the "ebb and flow" variety, also known as "flood and drain" construct. Nutrient-rich solution pumps periodically to plant roots, then flows away. Roots are not left submerged, where they could lose access to oxygen and drown. In most systems, roots grow into a planting medium to provide them with structure, such as clay beads, vermiculite or pea gravel.
Roots in Air
Aeroponics is another type of hydroponics that houses plants in buildings that maintain 100 percent humidity. Fine sprays of nutrient solution coat the roots at regular intervals. Advocates claim that plants grown this way are even more productive than those grown with other hydroponic systems.
Plants and Fish
Aquaponics incorporates the natural ecosystem that exists between plants and animals to produce two commercial products. Tank-raised fish produce nitrogenous waste that is toxic to them, but complete nutrition for plants. Pumping tank water to the roots fertilizes the flora and cleans the water for the fauna.
Just about every vegetable and herb in the marketplace is grown commercially with hydroponic methods. Yields are higher, disease is much reduced and easier to control if encountered, water usage is less. Soil-raised crops still dominate our food supply, but the hydroponics industry, especially in aquaponics, has grown exponentially in recent years. As research into this field expands, and expenses drop, hydroponically-grown food will become more commonplace.