Words & Photos: Rebecca Lees
Illustration: Narelle Denmead
I never would have thought that tiny microscopic creatures, poured on the garden in the billions, could do such a superb job at nourishing my plants. That is, until I learned about them, started breeding them, and witnessed the proof myself.
Beneficial microorganisms, within the soil, play a pivotal role in ensuring life below ground – and also above it – remains healthy and robust. They may be tiny, but the role they play in the intricate web of life is enormous; civilisation literally depends on them.
A while back I was given a book called Teaming With Microbes, by Jeff Lowenfels and Wayne Lewis. In the book they talk about the ‘soil food web’; the complex interactions between living things (from tiny bacteria to large mammals) and how by eating and being eaten (among other things) they sustain each other and natural ecosystems.
Healthy soil should be writhing with life. Some life forms in the soil you can see with the naked eye (worms, beetles, springtails), but much of the life within the soil you cannot (bacteria, nematodes, fungi, protozoa). People love pouring all sorts of concoctions on their gardens, some are helpful for soil life, but many are not. Some products can upset the natural balance of the soil life; they might kill pests, but in doing so can wipe out whole species of beneficial organisms. This disrupts the interactions within the soil food web, opening the system up to disease or dependence on foreign inputs.
To keep our gardens, and the soil food web, healthy and alive we need plenty of beneficial organisms living in the soil. These ‘good guys’ help keep our garden healthy. For example, there are creatures in the soil called nematodes. They are one of the most dominant species of animal life on earth, and one of the most ancient. There are different types of nematodes, some are beneficial to plants, as they mineralise nutrients and make them available for plant uptake. Other nematodes are not so helpful, feeding on the roots of plants. Also within the soil are fungi. Here’s where it gets interesting – fungal hyphae can wrap themselves around root-eating nematodes, trapping them and disallowing them to penetrate into the root of a plant. Fungal hyphae – the beneficial microorganisms – literally protect the plant from being attacked by a nematode.
Down in the soil there is a constant battle going on between good guys and bad guys. In a teaspoon of good soil there can be billions and billions of living organisms. In a teaspoon of dead soil, there can be none. We want truckloads of the good guys in our garden, and less of the bad guys. But how do we ensure our soil is full of these beneficial microbes?
There are several ways to do this; encouraging the types of microbes different plants prefer, using the best organic compost you can find, laying particular mulches on particular plants, protecting the creatures living on your property (they all play important roles in the soil food web), and promoting mycorrhizal fungi, are just a few.
One simple way we’ve employed of promoting beneficial microbes within our soil is by making actively aerated compost tea. This allows us to inoculate the soil with billions upon billions of beneficial microbes.
Actively aerated compost tea is not the traditional compost tea most gardeners are used to – those ones that smell horrid as they’ve been sitting around for weeks stagnating. Those types of tea are anaerobic, they lack oxygen and are therefore breeding grounds for the bad guys; anaerobic pathogens, or E. coli for instance. Not the sort of thing we want spread around our edibles.
The tea I’m talking about is a modern form, one which is continuously aerated, through the use of an air pump. A simple mixture of organic compost, molasses and water, with air continuously pumped through it.
How does the tea work? The compost brings beneficial organisms to the mix (the type we want to breed), the molasses gives those organisms the energy to multiply, the air ensures the microbes that do multiply are the beneficial ones. The aeration action strips the microbes out of the compost, and into the water, allowing them to breed.
Made well this simple brew becomes a sweet-smelling concoction, packed full of beneficial microbes, which is applied onto the garden immediately. We’ve been experimenting with this tea, with fantastic results. Cheap to produce, and simple to apply, the compost tea can be added directly to your soil and sprayed onto foliage. It puts the microbiology back into your soil, nourishing the soil food web, and helping grow healthier, more robust plants.
So, how do you make this liquid gold? Rebecca will give you step-by-step instructions in issue 444 – out June 27.
