What Makes Your Dirt Good Soil
No Respect
Well, we may know more about soil & celestial bodies now than people did in Signore da Vinci's time, but soil continues to get no respect. It’s still unnecessarily eroded & depleted. It’s scoured with herbicides, pesticides and quick-fix artificial fertilizers, powerful stuff that upsets the intricate balance among organisms and natural chemical exchanges maintaining soil & plant health & fertility.
Healthy dirt=healthy soil chemistry=healthy plants/animals/microbes=healthy us.
The Nature of Soil
Soil is a complex living system.
The fertility of our backyard or communal garden spaces depends on the health & diversity of the living organisms and the chemical exchanges they promote in our soil. Not only can we grow our own good healthy food, but we can also do our little bit for the planet by learning how to support biodiversity in our own patch of garden.
Soil is Minerals.
Eons of battering by wind, water and sun breaks down rocks into fine particles. Not yet soil, these mineral particles start to support some plant growth, and plants’ roots push deep into the rocky proto-soil, breaking it up even more. Then the plants die and decay, leaving the organic matter mineral particles need on the way to forming good dirt.
Soil is Humus.
Soil is the result of a fertile union between the mineral & organic worlds. One of its core ingredients is humus, decayed organic matter that has passed through the guts of earthworms and a mob of microbial decomposers.
Humus binds up many of the elements necessary for plant health (such as nitrogen, potassium, phosphorus, calcium and many others), and keeps them from being washed out of the soil. Humus also amends soil fertility by aggregating it, forming a texture that enhances its permeability by water and that supports the growth and necessary chemical exchanges among plant roots, beneficial bacteria & fungi and the myriads of other tiny critters living out beneficial lives in our dirt.
Finished compost is humus, so it's good to have a compost pile or two near your garden. Making a compost pile
Soil is a Web of Life.
Good, fertile soil is full of critters. Of course it’s interesting to research what kinds of organisms live in your garden soil, what they do there, and how they benefit your veggies. And the more we know about the good work the visible ones do, the less inclined we’ll be to stomp on them because they look vaguely sinister. Likewise, the more we know about the invisible ones, the more care we’ll take walking on, disturbing and feeding the good earth that feeds us.
Partnerships among bacteria, fungi and plant roots help to circulate nutrients from deep down up to the topsoil and back down again when the plants die and decay. Long, extremely tiny filaments of fungi infiltrate cells in the root hairs of plants, bringing minerals and water from deep in the soil in exchange for sugars the plant makes via the sun's energy.
Healthy garden soil is inhabited by (from largest to smallest) moles & voles, slugs & snails, potworms, earthworms, insects & insect larvae, rotifers (tiny predators who eat bacteria, protozoa, fungi & algae), springtails, mites, nematodes, protozoa, bacteria and actinomycetes.
BTW, actinomycetes are very interesting and important little beings. Not only do they help decompose organic matter; they're sources of antibiotics that control the overpopulating tendencies of pathogenic bacteria in the soil. Nature is millions of years more experienced in the use of antibiotics than we are!
The point is that healthy soil supports communities of creatures that exist in balance. They aerate the soil, convert organic matter to humus, and use nitrogen gas from the air in the soil to make nitrogen compounds needed by plants. Feeding and feeding off each other, many produce compounds that nourish and protect our garden vegetables— even with antibiotics!
How You Can Support the Wellness of Your Veggie Garden Soil.
1. Avoid using synthetic fertilizers.
2. Add organic matter and humus back into your soil regularly. Working on your soil’s texture & supporting its biodiversity will produce healthy, disease- and pest-resistant plants. Pick off & destroy any visible insect pests you find. You won't get 'em all. But there can be relatively peaceful coexistence.
3. Mulch regularly.
4. Organic gardening is based on the principle of ‘balanced return’. Do as Nature does. When plants die, their remains decay on the soil surface, feeding the microbial decomposers (bacteria and fungi) that produce many of the compounds plant roots need to be fruitful & multiply.
5. Chop up your spent plants and weeds that haven’t yet gone to seed, dig a trench at least a foot deep, bury them and plant new seeds or seedlings over top of them. Your ‘dead‘ plants will return what they’ve taken (and a little more) back into your soil and to your new plants.
6. Besides sunlight & air, the most important factors promoting healthy soil & healthy plants are: Mulch, Microbes & Moisture.
References:
Harris, Marjorie. (1996). Ecological Gardening. Random House of Canada, Toronto.
Nardi, James D. (2007). Life in the Soil. The University of Chicago Press, Chicago.
Our own dirt.
We know more about the movement of celestial bodies than the soil underfoot.” Leonardo da Vinci (1452-1519)
Urshanabi, Tiller of Earth
