Actively Aerated Compost Tea: Nourishing and Protecting your Gardens, Fields, Pastures, and Trees Using the Power of Mother Nature

posted in: Compost, Soil | 0

By Marc Doll, Foot Forward Forest Farm, Quadra Island

In 2015 I discovered that everything I thought I knew about soil and compost was wrong.

Up until then I believed that soil was nothing but a repository of the minerals that plants required to grow. When you added water to that system, the minerals dissolved and the plant’s roots then sucked up that Nitrogen, Phosphorus, Potassium, and other minerals like a child does a chocolate milkshake. Truth be told, I wasn’t totally wrong, plants in a healthy system do absorb 1-2% of their total nutrients this way.

Interestingly, it is this chemical view of soil which is the driving force behind our industrial, chemical-based food system. It is also this chemistry-focused agriculture that has temporarily increased our agricultural production, but at the cost of killing most of the world’s topsoil, as well as creating new and wondrous chemically resistant pathogens, and contributing to climate change nearly as much as the fossil fuel industry… but I digress… Let’s focus now on the other 99% of how plants get their nutrients.

On that faithful day in 2015, a day which would rock my world view and help set my life down a completely different path, I went to a symposium in Invermere, Alberta, hosted by Dr. Elaine Ingham. It was here that, for the first time, I saw soil, real living healthy soil, under a microscope.

What I saw there was not some chemistry experiment, but an amazing living world of bacteria, fungus, micro-arthropods, amoeba, flagellates, nematodes, and so much more. It is this microscopic, biologically-dynamic world of soil that feeds, protects, and allows life to flourish. Soil is biology not chemistry.

Real compost, I would then learn, is not a fertilizer nor is it about adding organic matter to soil, rather it is about inoculating it with plant nourishing life.

Elaine’s career, which began with a PhD in ocean microbiology, soon evolved into the study of soil and eventually the development and popularization of the concept of the “Soil Food Web.”

Fear not… I’ll get to Actively Aerated Compost Tea in a minute, but to understand its power, I have to spend a couple more paragraphs on the world brought to life through the lenses of my microscope.

It is the “Soil Food Web,” and not fertilizers, that feeds our plants. It is not ‘icides (fungicides, insecticides, etc) that protect our plants, but instead it is this same soil food web.

We do not fertilize the forest, yet it towers overhead with more verdant life than our gardens will ever produce. We do not adhere to the “more-on” philosophy of pouring endless NPK fertilizers and herbicides in these same forests yet still they thrive. The “weeds” many fight daily in our garden are not present in an untouched meadow.

The source of all of this above ground photosyntheticly powered life can all be seen moving, reproducing, growing, eating, and most importantly, pooping, under a microscope at only 400x magnification.

Everything we have trusted the Monsanto/Bayer mega corporations, and former munitions makers, to do for us, through the production of some new magic fertilizer, herbicide, or pesticide, is naturally done by this fascinatingly complex microscopic world. Harnessing the power of nature’s natural soil life system is simply a question of reintroducing it, in the right proportions, back into our human-disturbed garden, lawn, pasture. Field, and orchard systems.

This brings us to compost tea, or more precisely, to Actively Aerated Compost Tea (AACT).

The single most effective way of introducing or enhancing soil life in our garden, lawn, pasture, field, and orchard systems is AACT, but let’s first look at how it is made to understand what it is.

AACT takes a relatively small amount of compost (in my case about 10-12 pounds in 50 gallons of water), and through a 2-3 day brewing cycle, multiplies the life from that small literal “tea bag” of compost, into the liquid equivalent of tons and tons of compost. Instead of adhering to organic matter as in your home compost pile, this life is swimming, eating and multiplying exponentially in a highly aerated and nutritious liquid solution, enhanced with a variety of minerals, as well as added bacterial and fungal foods. This living solution can then be applied to anything we wish to grow, enhance, or protect as simply as by putting it into a watering can or a sprayer.

Here is a photo of what I would typically see under the microscope when looking at a successful compost tea:

Every little circle or rod-like structure, ranging from the size of of pencil dot to that of a small felt tip marker, represents a single bacteria. The brown ladder-like structures are beneficial fungi. The large blobs filled with recently consumed bacteria are amoeba. Missing from this shot but present in a good brew are flagellates (1/4 the size or smaller than a typical amoeba), nematodes (which would cross the whole field looking like a transparent worm), and mico-arthropods (which appear in your nightmares for a few weeks after you see them under the microscope, they are so scary looking!). And happily you see no ciliates.

What you are looking at here is a highly concentrated plant-feeding and protecting biome, not a fertilizer. The minerals present in the above slide are not bio-available to what we want to grow. The soil food web makes them bio-available. The fungal hyphae mine the micro-nutrients from the mineral crystals, which is then eaten by a nematode. That nematode then dies and is consumed by something else which is then eaten by something else…. All the way along those “somethings” are doing the most important biological process in our soils and growing systems: they are pooping. It is this trillions strong army of subterranean poopers that, much like their above ground distant cousins, the ruminants, provide the poop that then feeds and protects everything we want to grow.

Mother Nature has made this biome relatively easy to understand. In broad strokes, anything that can live and reproduce in an aerobic system is beneficial to our plants. Anything in an anaerobic system is potentially caustic or a vector of disease.

I mentioned earlier that it was a cause for happiness that no ciliates were present in the slide. Ciliates thrive in anaerobic conditions and are a sign that that particular brew did not provide enough oxygen to promote the right type of life. This is why every batch of AACT needs to be closely monitored and examined under a microscope before application. We want to enhance the biome that acts as an immune system and feeds our plants, and not the anaerobic world of garden, tree, and field pathogens. YouTube is full of videos of people attempting AACT using fish tank bubblers or some other small aerator. Unfortunately, so much life is present in a good batch of AACT that these small aerators can not introduce enough oxygen to keep the brew aerobic, and this lack of oxygen provides the perfect conditions for pathogens to flourish. There are 2 basic principles that need to be applied to the propagation of AACT. First, enough air needs to be applied to the system to keep it looking like it is in a “rolling boil,” and second, never apply a tea before verifying its health under a microscope. A simple mistake in the amount of bacterial food in a brew can make even a fully aerated tea go anaerobic.

AACT is used to replace every type of “icide.” Instead of a fungicide, AACT provides your system with the beneficial fungi which will out-compete the pathogenic weaker fungi. It also enhances the fungal eating nematode count, which thankfully prefers the weaker pathogenic fungi or “oomicites.”

Instead of dumping life killing NPK fertilizer into your soil, AACT provides the life which mines, digests, and then provides in bio-available form everything the plant needs right to its root zone, all without polluting natural waterways or creating ocean dead zones.

Instead of insecticides, AACT inoculates your system with the microbes, fungi, and micro-arthropods that feast on insect larvae in the soil.

Instead of spraying our trees with sulphur as a natural fungicide, or other significantly more toxic chemical fungicides, which don’t discriminate between good guy and bad guy fungi, AACT provides the life which enhances the natural immune system, filling all the niches with beneficial life and thus reducing rusts and blights in our orchards.

AACT and the soil food web have, since that faithful day in 2015, become a point of passion for me. Bringing the dead pastures that came with my farm back to life, building verdant garden beds that provide for my family, and growing amazing fruit, all without using a single drop of any chemical, has become my life focus. It is certainly difficult to squeeze a coherent portion of years of learning into a single post but I certainly hope you found this blog informative.

If you have any other questions, feel free to send me a message:

Marc Doll is a regenerative farmer and passionate soil re-builder living on Quadra Island.

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