First, let’s get clear about the difference between “dirt” and “soil,” because just the sound of those words pretty well says it all.
Dirt is what’s on the driveway and kitchen floor, whereas healthy, living soil is rich and dark brown in colour, has the heavenly scent of damp earth, is slightly crumbly to the touch and loaded with worms, bugs, microbes and other life forms.
Soil is the foundation of everything we do in our landscapes and food gardens and we want to have plenty of it – and not only for our sakes, but also for the critters that depend on it.
The soil food web in living, healthy soil is a highly sophisticated, biologically active, interconnected and interactive environment of untold billions of busy micro and macro soil organisms that are continually eating, digesting, multiplying, gas converting, pooping, tunneling, etc. These critters are the fungal and bacterial microbes, worms, insects and other microscopic organisms, all playing a critical role in the soil health and structure and dependent on each other for survival.
In other words, this is an ecosystem and a habitat that these soil dwellers have created for themselves – depending on the conditions they find themselves in – and we don’t want to muck with it by digging, flipping and tilling it all up.
It might look nice and tidy and weed-free afterwards, but you’ve just collapsed it by literally turning their world upside down.
Over and under-watering, suffocating the system with landscape fabric and using toxic fertilizers, pesticides and herbicides will also doom this precious ecosystem.
So what do we do instead? Nature has a top-down method of gardening. Organic matter such as leaves, needles or anything else that descends from above, is continually dropping on the surface, which we call the litter layer. (We create a litter layer by mulching).
The soil organisms and worms then do their job of breaking it down into smaller, more nutrient-available forms for your plants and other soil dwellers to take up.
The end or stabilized product is a fine, dark soil called humus, which acts like a nutrient and water holding tank and the amount of that wonderful stuff depends entirely on the amount of fresh organic matter you add to the food web.
In the meantime, the worms (who depend on this litter or mulch layer) will not only multiply, but will continue to tunnel away, creating air spaces, places where plant roots can travel more easily and water can flow more freely.
In order to create or re-establish the soil food web in your garden beds, add a good two to three-inch layer of a diversified mulch cover (I mix, one-third each of year old wood chips, fresh grass and shredded leaves), which will provide food for the macro and micro critters, then let them do their thing.
You can also re-establish your microbes and increase the nutrient level in your soil by adding some good compost tea or you can even buy microbes on-line through the Organic Gardeners Pantry located in Victoria. Over time, and with a continual good food supply on the surface, the critters will build a healthy, living soil that you and your plants will love.