One of the more interesting developments of the past decade has been the surge in products containing mycorrhizal spores - potting mixes, inoculants, fertilizers, etc. Of course, some of these are nothing much more than marketing gimmicks that add a teensy amount of mycorrhizal inoculant so the label can trumpet "Contains Mycorrhizae" in huge bold letters.
If one looks at the back label, you usually find that the spore count consists largely of inexpensive Ecto-type spores that are about a dime a million. However, for most growers Ecto spores are of no value. Fruit trees, vegetables, turf grass, grapes, and most flowers all match up with Endo types. Rarely will you find any significant numbers of the far more expensive Endo spores in mass-market retail products.
This is not to say that every potting mix or soil additive must have huge concentrations of spores to be useful. For example, our MycoMinerals(TM) product is mostly essential minerals and growth stimulants, with relatively small numbers of both Endo & Ecto spores added.
MycoMinerals has a minimum of 500 Endo spores per lb., (plus 5 million Ecto for anyone dealing with pines or oaks, such as bonsai growers) and at an application rate of 1 lb. per 50 square feet, plant roots will encounter more than enough spores to create the desired colonization. When a product is intended to be used in this manner, there is no reason to include more spores.
By way of comparison, our inoculant products will have roughly 35,000 Endo and 35 million Ecto spores per lb. - but they are not intended to be used as a general soil additive. These inoculants are usually added in tiny amounts to the roots of individual plants or seeded fields, where the goal is simply to introduce the beneficial fungi to larger-scale fields, orchards, or vineyards. These sort of applications call for much more concentrated spore counts.
But note that spore counts can also be too concentrated for convenience. Remember that the spores are microscopic and need to be in a carrier material of some kind to be handled and measured. We use a finely ground version of the trace minerals and some proprietary biostimulants as a carrier - with a spore concentration that results in a teaspoonful having the right number of spores for a fruit tree or grape transplant.
I am noticing more and more orders from potting mix and fertilizer companies that are using our products as an ingredient, often in combination with beneficial bacteria and other plant-friendly organisms. To me, this is an indication that biological additives are turning into an important marketing category with great growth potential (no pun intended). Some very bright people are developing intelligent products that produce superior growing results - and are being rewarded for their efforts.
I really enjoyed conducting many hundreds of experimental grow-tests when I started BioOrganics, and then again when we introduced MycoMinerals several years later, so I'm all for encouraging these new soil-product entrepreneurs who are now doing their own R&D. Tomorrow's growers will certainly have far better choices than between incomplete 10-10-10 or 20-20-20 synthetic fertilizers. I can foresee many different biological "cocktail" mixes becoming available (regional, by crop type?).
We are also seeing that advanced organic techniques using microbial additives can out-produce chemical routines, or can bring orchards/vineyards into bearing at earlier ages. Pricing is still usually an advantage for petrochemical fertilizers, but as the price of oil goes up future farms and gardens will be looking for more cost-effective alternatives.
The dozens of smaller companies now developing biological-input products are doing their part by testing and packaging, and will be ready to expand any time. Look for these new bio-items at your local supply store or garden catalog. I think you'll like the results.
Good growing, my friends,
Don Chapman