Hydroponics

Types of Engineering involved: Agricultural

How do you grow crops in places like the Arctic and the Sahara; places where there isn't enough soil, rain or sunlight? You might try hydroponics.

Hydroponics is the science of growing plants without soil. It is used to overcome the limitations of traditional agriculture - inadequate water, poor soils, short growing seasons, excessive heat or cold, or inadequate light. Hydroponic produce like lettuce and tomatoes - can be grown any time of year at any latitude, no matter the weather. Imagine going to the grocery store or co-op and buying a tomato marked "Product of Nunavut"!

In a hydroponics system, the plant roots are not in soil: sometimes they hang down into containers of water; other times they might be in some type of material, such as rockwool, which holds moisture really well. Water is delivered to the plants through tubes in automatically timed doses. All the nutrients and minerals normally found in soil are contained in solutions dissolved in the water. Where access to water is an issue, aeroponics might be used. In this process plant roots hang in mid-air and are continually sprayed with a nutrient solution mist.

Because hydroponic plants are grown without soil, they are not exposed to weeds or soil-borne pests. Plants grown this way maintain ideal nutrient and moisture levels; they are healthier, more disease resistant and grow up to 30% faster than other plants. The root systems of hydroponically grown plants stay smaller, so the plant's growth energy is concentrated on producing plant mass. The small roots also allow the grower to have more plants per square foot of garden space.

Hydroponics may sound new and very scientific, and in fact it is one of the ways that astronauts on long space missions would grow food, but Aztec farmers used a system similar to hydroponics for growing maize and greens more than 700 years ago. By building sod bridges over freshwater lagoons, they ensured that crops would receive both nutrients and water on an ongoing basis.

Some of the information in this article was derived from interurban and College of Agriculture & Natural Resources