I've just finished reading about inoculating wheat seed in some Nebraska test plots with mycorrhizal spores. A very small amount of inoculant produced good yield increases over comparable control plots during a drought year.
The results came as no surprise to me - most areas of the midwest have been so intensely tilled and synthetically fertilized that the once-abundant beneficial bio-life in the soil has been nearly eliminated. Restoring these important biological elements to plant root systems almost has to produce observable benefits.
I think it is inevitable that soil scientists will all someday come around to the realization that soil biology is at least as important to plant performance as are NPK levels, and I'd make a strong argument that the microbial life in crop soils is actually far more important.
In general, most of us have trouble really and truly grasping big abstract ideas such as "sustainable agriculture". Such long-term concepts, no matter how important, always tend to get overshadowed by immediate issues. (It's hard to remember that your game plan was to drain the swamp when you're up to your rear in alligators!)
If a soil sample shows that the soil pH is on the low side, or so many units of N per acre has always produced good yields in the past, then it would be the rare modern farmer who hesitates to use the recommended chemical inputs for each season's plantings. I would wager that not one out of a thousand of them thinks about harmful effects on soil biology.
At a glacial rate of progress, this may be changing. The USDA is actually beginning to notice that soil problems may be linked to the destruction of beneficial organisms. True!
To quote from an ARS News Service release, "When you think of endangered species, you never think of soil fungi. Yet the fungi that make plants hardier have had their numbers greatly reduced by the intensive agriculture practiced in the United States since the 1950s. Agricultural Research Service scientists are trying to figure out how to put these beneficial soil fungi back, as farmers make the transition to using less chemicals... Farmers today have to rely on whichever of these native fungi survived years of chemical use…"
I don't know whether to feel good or feel nervous when government bureaucrats agree with me, but even if this idea goes nowhere fast within the USDA, as I would expect, someone there seems to be actually concerned about restoring soil fungi. If interested, you can read more about this research at http://www.ars.usda.gov/is/AR/archive/may01/fungi0501.htm
As I mentioned in an earlier newletter, an internationally-respected soil scientist told me that he was worried that massive crop failures in the U. S. would begin occurring by the year 2025, if not sooner. He felt that our rich soils were being burned out by too much nitrogen fertilizer in a push for higher and higher annual yields. His theory was that there are very specific critical lines in soil for such things as living organisms, trace elements, and humic matter. Above the lines, plants will survive and below them they cannot. Consequently, he thinks there will probably be sudden dropoffs from one season to the next, rather than gradual yield declines, as lines are crossed.
Now, I'm not saying he's right and I'm not saying he's wrong. Time will tell. I will say that his dire prediction does tie into the USDA idea that we are not taking very good care of our precious food-producing resource - soil. As we kill off its bio-life, soil becomes compacted and salt levels increase, eventually leading to decreased yields if not sudden disasters.
I hope there will be many more soil scientists conducting in-field trials involving biological methods. I would think there is greater potential value to be found there than comparing the effects of one NPK fertilizer to another. If any of you are aware of such bio-trials, please let me know. (I'm aware that there are thousands of lab test results available, and they are useful, but I'm far more interested in learning about real-world applications.)
Cheers,
Don Chapman
President, BioOrganics, Inc.