For those of you who have been reading these newsletters for a while, you know that I often use my vegetable garden as an example of biological growing methods.
Several years ago, when I first began experimenting with mycorrhizal fungi, I stopped my old ways of rototilling and putting synthetic fertilizer in the soil every spring, with added sidedressings and cultivation during the season. While this routine served me reasonably well for more than 45 years, my research into beneficial microbial organisms indicated that tillage and abnormally high fertility are harmful to mycorrhizal fungi.
Having an ultra-productive vegetable garden that is based on biological, rather than chemical, principles has now become such a routine thing to me that I hardly take notice of the big yields except when a neighbor visits and makes a fuss over the plants. "What fertilizer are you using?" is their usual question.
I've gotten used to seeing their puzzled looks when I explain that I never dig the soil and use hardly any fertilizer - just a very light scattering of compost, dry fish pellets and some volcanic trace minerals scratched into the top couple inches of soil early in the spring.
I think the most important lessons I've learned from my garden are:
- 1. Tillage, especially "fluffing up" clay soils with rototilling, is counter-productive. It makes the beds nice and loose for a few days, but if there is limited biological activity in the soil, they quickly revert to a hard-packed condition. I've found that the no-till concept - just lightly scratching nutritional materials into the surface - is gentler on the valuable living organisms that keep the soil loose without human help.
- 2. Replicating nature's own "from the top down" method of replenishing nutrients works better than blending fertilizer deeper into the root zone. Artificially enriching the soil several inches deep might seem helpful to plants, but letting earthworms, bacteria and fungi do the job of transporting the nutrients down lower in the soil seems to be the better strategy.
- 3. The amounts of fertilizer commonly recommended by manufacturers and "soil experts" are excessive and harmful to beneficial soil organisms. Small amounts of slow-release materials that contain a very broad spectrum of major, minor, and trace elements are preferable when following a biological approach to growing plants.
- A covering layer of mulch conserves moisture and discourages weeds. This step completes all my fertilizing and cultivating for the whole season. Almost too easy!
Some of these same procedures are catching on in agriculture - especially no-till or limited-till, although from what I read, the practitioners are mostly unaware of the biological reason these methods work so well. They are unintentionally encouraging beneficial organisms!
But we must always keep in mind that it is a mistake to think of gardens as just little farms, or of farms as just big gardens. The differing scale of operations call for differing methods, plus farms have profit considerations which are absent from home gardens.
However, both gardens and farms can benefit greatly from the "cheap and clean" low-input assistance of living soil organisms, and I think there is a role-reversal of sorts happening as ag researchers look at successful biology-based gardens for new ideas.
Motto for the day: Take care of your fungi, and they will take care of you.
Cheers, my friends,
Don Chapman
President, BioOrganics, Inc.