Aeroponics is Unique
Aeroponics is the practice of growing plants in a closed environment without the use of soil or an aggregate medium. It’s similar to hydroponics, but where hydroponics keeps roots primarily bathed in oxygenated nutrient solution, in aeroponics the plants and roots are suspended in the air. Water and nutrients are provided by misting or fogging at specific intervals. Since the roots in aeroponics setups are primarily exposed to air, they have unparalleled access to oxygen which promotes explosive growth.
Aeroponics as a concept has been in use since the 1920s but it has become popular only in recent years, probably due improved technology, profitability, and the changing pressures of global food production.
In Aeroponics, there is no growing medium at all. Plants are suspended in midair using a foam or specially designed tray that gently supports the plant stem while allowing it to grow. In both hydroponics and aeroponics, plants are provided with the necessities of life: moisture, nutrients, and oxygen. Since these resources are readily available, plants have no need to spend valuable energy seeking them out, like their soil-grown equivalents. This allows plants to focus all their energy on growth, flowering, bearing, and reproduction.
In traditional hydroponics systems, crops consistently grow more quickly than their soil-grown counterparts. In aeroponics systems, however, growth tends to be even faster, given the unlimited supply of oxygen, while nutrient uptake is optimized. This not only supports rapid, robust growth but produces crops with excellent nutritional profiles.
Considerable research has been conducted using aeroponics systems largely because the sealed growing environment can be very closely managed for a wide variety of conditions, including low gravity environments. The carefully controlled environment also minimizes the threat of many diseases since root chamber can be kept sterile, while the exposed roots are never soaked in a stagnant, moist medium where pathogen-carrying debris can collect.
Today, aeroponics is considered one of the best methods for growing plants in a soil-less system. There are many reasons why the practice of hydroponics in general and aeroponics in particular are experiencing rapid growth, including highly efficient use of scarce water resources, very small footprints that make food production a viable concern even in urban environments, and the ability to produce food without fear of soil contamination and polluted runoff.
Rapid Growth, Exceptional Yield
The primary gain from aeroponics is rapid, robust plant growth that yields exceptionally healthy, uniform, and vigorous crops. Research conducted by NASA has demonstrated that plants grow up to 3 times faster than their soil-grown counterparts. Much of this exceptional performance is possible because plants in aeroponics systems enjoy access to plentiful oxygen at all times.
The whole package of aeroponics benefits (including year-round production and grow lights) accumulates for even more impressive results. In some studies, aeroponics techniques have been credited with yields up to 10 times the yield of conventional production techniques.
Lower Resource Use
The defining growth environment of aeroponics systems translates to a greatly reduced demand for both nutrients and water. Initially, that seems counterintuitive because the high growth and productivity associated with aeroponics is closely associated with the availability of nutrients, water, and oxygen.
Aeroponics plants grow suspended in air and receive moisture and nutrients by way of a fine mist applied directly to the roots, almost all of which is readily absorbed. In contrast to traditional hydroponics, where root systems are bathed in a constantly moving stream of nutrient solution, much lower volumes of prepared solution are applied. In addition, plants grown in aeroponics setups are able to absorb more nutrients than plants in other environments because the nutrient solution is optimized for maximum absorption.
In situations where fresh, clean water is at a premium, aeroponics systems make a lot of sense. In fact, estimates indicate that aeroponics uses 90% to 95% less water than traditional farming methods.
Ideal Growth Conditions
The managed environments in closed aeroponics systems permit the fine tuning of individual components, including temperature and light cycles. Compared to traditional hydroponics, aeroponics optimizes root formation and limits water usage.
Aeroponics systems permit fine control of critical parameters in the nutrient solution like electrical conductivity (EC). EC refers to the concentration of minerals in the solution; if the minerals are out of balance, it can directly affect the plant’s ability to absorb the necessary nutrients. Highly mineralized (hard) water also affects the pH of the nutrient solution, which in turn affects plants’ ability to absorb nutrients. In fact, by simply measuring and managing these two factors in aeroponic systems, most nutritional problems can be avoided.
The Critical Role of Oxygen
Oxygen plays a much larger role in the life and health of plants than is immediately apparent. For humans, oxygen is perhaps the most basic requirement for life, but we live above ground, on land, where we are surrounded by air all the time. It’s hard to separate the benefits of oxygen in terms of our health and growth from our everyday existence. We know that plants exchange oxygen and carbon dioxide through tiny pores called stomata in their leaves and stems. But plants “breathe” through all of their parts, including their roots. In the root zone, oxygen is absorbed to release energy which is, in turn, used to transport nutrients (minerals and salts) from the soil. In traditional farming and horticulture, soil is turned, amended, or otherwise treated to maximize air pockets, allowing roots to reach oxygen without too much effort. Roots are capable of taking oxygen from the water for this purpose, but not as efficiently as from the air.
Hydroponics operators address this limitation by aerating the nutrient solution as it flows past the plants, maximizing the amounts submerged roots can absorb.
Oxygen’s role in plant growth can’t be understated. Glucose, produced in leaves through photosynthesis, is used to generate cellulose and starch as well as fueling other metabolic processes. Glucose is also consumed by root cells and transformed into cellular energy that drives water and nutrient uptake. Without oxygen, glucose cannot be transformed into energy and roots, in turn, cannot take up water or nutrients.
In the end, it’s the root system’s access to oxygen that is the ultimate limiting factor in crop growth. Without oxygen, roots cannot absorb water or nutrients, which slows plant growth and limits the ability of the plant to photosynthesize. In turn, there is less glucose available for the roots to use in order to absorb water and nutrients. It’s an ugly cycle leading to stunted growth, increased susceptibility to disease and environmental stressors, and low or poor quality yields.
Even traditional soil farmers have studied the importance of root respiration by supersaturating their irrigation water with dissolved oxygen (DO). Studies demonstrate that this can increase plant growth and quality, promote overall crop health, and reduce time to maturity.
No matter what system is used to produce crops, healthy roots with a good supply of oxygen have better respiration. This allows them to selectively absorb more of the vital mineral salts nitrogen, phosphorus and potassium. When there’s less oxygen in the water than there is in the plant, this reduces the permeability of roots to water, therefore reducing (even reversing) the absorption of nutrients.
Aeroponics, by definition, provides unlimited access to air, along with regular application of micro-droplets of water and nutrients. It’s an ideal system to provide plants with a highly optimized growing environment that maximizes growth, production, and overall health.
