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Re: Beneficial Soil Microbes
I'll leave the EM aspects for EM folks to answer.
But, you ask a question about the specificity of the organisms in soil. Are they specific to the soil, to the plant species, the temperature, moisture, clay, organic matter, humidity, the kind of earthworm, microarthropod, nematodes, or what?
Maybe there are some generalist species. How much do the species change through the course of the day or week, or year? They change based on the things listed above.
What happens when a weed arrives? Or a new plant species? What happens when a bird lands on the soil? What happens when a new bacterial species arrives that has not been there before? What if that species is better able to survive under the conditions in the system than the organism already there?
As plants species change through the course of succession, do the bacteria, fungal, protozoan and nematode species change? Yes they do. So, how can that change occur if nothing that arrives in the soil can survive?
You make soil sound like a static thing, once the organisms are there, they never change. That's a very incorrect view. Soil is dynamic, changing, shifting, one-organism waking up, others going to sleep and everything in-between. There is no set absolute group of organisms in any soil. It is a moving target, changing as each organism alters and changes soil properties.
What drives succession? What we see is that there's a good probability that the ratio of fungi to bacteria drive succession. This measure certainly changes in a consistent pattern through succession. I am about to get the next paper published, with data showing how that ratio changes, given hundreds of samples taken in each ecosystem, each successional stage.
Species composition does not remain static. Nor does the precise number of individuals per each species on each day, but there's a range within which these numbers revolve.
Think of the fact that protozoa eat 10,000 bacteria a day per individual, and there are 10,000's of thousands of protozoa per gram of soil. Do you suppose that might leave a foothold open for a new species to survive, if the conditions are right?
How many species of bacteria and fungi present after the soil has been treated with a fungicide? A bactericide? A nematicide? Every pesticide that we have ever tested has non-target organism effects. You are killing someone beneficial in soil when you use any toxic chemical.
High levels of inorganic fertilizer kills soil organisms too. After years of pesticides and fertilizer applications, is the normal number or species diversity of organisms still present in any soil?
Absolutely not. The proper set of organisms needs to be added back into the soil. Addition of compost, or compost tea, does that. The beneficial organisms are no longer present in soil after being killed by toxic chemicals. But the se organisms do not magically arrive on the wind. Because they have been killed in the soils upwind too. So, where do we find the inoculum to put these missing beneficial organisms back?
Compost, compost tea. BUT it has to be properly made compost, not some putrefying organic matter. You don't have the beneficial organisms in a stinky, smelly mess.
EM contains 80 species of bacteria and three species of fungi. Enough species? Can you replace lost functional groups of organisms with just 80 species of bacteria?
What if you have also lost fungal species? Protozoa? Beneficial nematodes? The EM inoculum is not adequate.
How many species of bacteria and fungi in compost? In compost tea? In soil?
Amazingly enough, the organic matter that is in compost is quite similar to, although perhaps more diverse than, the litter layer in any ecosystems. Mix the compost into the soil - you mimic the action of earthworms, cow hooves, buffalo, elk, deer.
Compost addition adds the foods to feed the organisms, and the organisms. You replace lost species. The right ones? Let the plant choose the right organisms, based on the exudates coming from the roots. If the organism was missing, but best adapted to the conditions in the soil, in the rhizosphere, in the litter layer, the bacterium, or fungus, or protozoan, or nematode, etc, will survive and grow.
It's a dynamic system, in equilibrium, constantly improving if not disturbed. Stop thinking as if it is static, set, not capable of change. Which organisms were killed and need to be put back? Add them by adding compost. We have no better resource, no easier way of adding a HUGE diversity of these needed organisms than by using good, aerobic compost, or compost tea.
President, Soil Foodweb Inc.