It bears repeating. Providing mycorrhizal fungi spores to plants is NOT giving them something "extra." It is NOT a miracle-plant-food-sort-of-thingy. It is NOT some sort of mystical additive.
Simply put, a plant without mycorrhizae on its root system is not equipped to uptake the necessary nutrients to flourish. You can fiddle with "soil chemistry" as much as you wish, and you may have some short-term success, but if the plant has evolved a dependence on soil fungi over millions of years, that plant will not achieve its full genetic potential without the fungi.
Someday, probably way down the road, it will be widely recognized that nutrients in the soil are not the only important factor for plant productivity. It is far more vital to move those nutrients into the roots on an as-needed basis. And guess what? That is precisely the role that mycorrhizal fungi have assumed. Most plants do not have roots that can do this job by themselves.
To a soil biologist, the frustrating thing is knowing that it can be so very simple to grow food plants that will perform at or near their full genetic potential. But 99 out of 100 growers just keep pouring NPK fertilizer on their fields in the belief that high yields come from expensive chemical methods.
You can plant a beefsteak tomato, drench it with water-soluble plant food every week, and have a decent harvest. I'll take an identical tomato transplant, put it in soil with a small handful of fish pellets and a teaspoon of mycorrhizal inoculant, not add anything else for the entire growing season, and will end up with at least a 50% greater yield than you - maybe 150%. And I'll do it year after year - the soil will never be depleted under a biological orientation.
Higher yields with lower input and long-term sustainability of our valuable crop soils - that's the promise of using biologically-based methods. Using beneficial microorganisms instead of petroleum-based fertilizers is a tough concept to grasp after decades of chemical methods, but the clock is ticking on chem-ag. If we want to leave our children some decent soil to grow crops, it's time to stop burning out our farm acreage and gardens with incomplete "plant foods."
Cheers, and good growing,
President, BioOrganics, Inc.