Actively aerated compost tea (AACT) is one of my all time favorite gardening tools. It is a great vehicle for harnessing the natural processes of nature and making them immediately available to the organisms in your garden. Nothing beats its simplicity and versatility.
AACT is brewed by extracting compost into water through the use of an air pump. The air bubbles provided by the air pump extract soluble nutrients along with all of the beneficial microorganisms that have been breaking down the organic matter found in the compost from the compost into the water. Microbe foods (such as molasses) that are rich in complex sugars are then added to the water, causing the microbes extracted from the compost to feed and multiply rapidly. As the microbe population grows, the brew is continually aerated to ensure that the entire tea maintains the aerobic conditions that discourage the presence of pathogens and anaerobic organisms. The result is a nutrient laden soup that is bursting with beneficial microorganisms.
Provide Plant-Safe Nutrition:
When we make compost tea, we are using air to extract the nutrients of our compost in the tea. This tea then becomes a valuable fertilizer, which can be applied foliarly or added to your soil or system water.
Because inorganic fertilizers utilize heavy doses of concentrated, pure nutrients, they can burn plants and strip the soil of beneficial microorganisms. Unlike most inorganic fertilizers, compost tea can be safely used in any amount (as long as you are not over-watering your plants). The nutrients in compost tea are in their organic state and locked away in the biomass of bacteria, ensuring a healthy release rate of nutrients over time.
Bolster Your Garden’s Microorganisms:
The true value of compost tea is not only does it provide nutrition for your plants, but it also gives your grow environment a massive boost in beneficial microorganisms. Since we are feeding the microorganisms during the compost extraction, they are able to multiply rapidly, making compost tea a great tool to replenish barren soil or even just introduce a wider variety of bacteria, fungi, and protozoa.
Compost tea is an effective pest deterrent. When applied foliarly (on the leaves), it not only provides your plants with extra nutrition, but inoculates the surface of your plant’s leaves with beneficial microorganisms which will compete for the food resources secreted by the plant, creating a pest resistant microbial barrier on the plant’s surface. Compost tea made specifically from vermicompost (compost comprised of worm castings) contain a special group of enzymes called chitinases, which break down chitin, a main ingredient in insect exoskeletons, making it an mild insecticide as well. Similarly, when applied as a root drench, compost tea will provide your plant’s rhizosphere (root zone) with beneficial microbes that will outcompete pathogens for food resources, and, as in the case of this nematode-eating fungus in the video below, even hunt down and destroy them.
Safe For You And Your Garden:
There seems to be a bit of controversy over the use of compost in aquaponics. Skeptics often claim it as a source for pathogens such as e. Coli. Although they are technically correct that a potential risk is present, anything you add to your aquaponic system could be a potential “source” for contamination. It’s worth noting that well formulated, aerobic compost is anything but dangerous. Decomposition is nature’s preferred method for creating plant available nutrients from waste, thus it is fully equipped to ward off and deal with potential pathogens. Whether the pathogens are eliminated by the heat generated by thermophilic bacteria in a hot process compost, or are outcompeted for food resources by healthy microorganisms during the maturation stage, a properly maintained compost pile is quite safe for any kind of garden.
Through the use of quality compost and the aerobic conditions provided by constant aeration, compost tea breeds healthy microorganisms present in the compost, providing yet another measure against contamination.
Cheap And Easy:
One of my favorite perks of compost tea is that it is cost effective. Once you’re past the initial investment of an air pump, a paint strainer and a five gallon bucket, you’re in business. Most of the ingredients used to brew can already found inside your house and in your own backyard. If you’re already a composter, then you have accomplished the majority of the work; the steps to compost tea are ridiculously easy.
As a side note: just because because the compost tea method is simple, doesn’t mean that it is devoid of depth. There is a whole world to perfecting recipes and studying the cultivated microbes to analyze your compost diversity.
Are you sold? Eager to start brewing your own microbial power teas? Good! I’ll be covering my compost tea process, as well as the how-to behind creating healthy compost that breaks down quickly in my next couple articles.
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