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Re: [compost_tea] soil versus compost diversity



I had told my website guy to put the Compost Manual up about 3 months ago on hte website, and had assumed it had been done, but apparently not. 

So, I updated it over the weekend.  It is about 60 pages, so I think it will have to be a book, not a website thing.  Or we will put it on the website, but as a pay-per-view.  Sorry, I need the money to be able to continue paying for the research we do. 

Soil does not have the variety or amount of organic matter that compost has.  The diversity of species, and the acitvity of the organisms is much lower in most soils than in correctly-made compost.  Notice I did not say all soils, so don't go off on me that there are exceptionsg, ok?  I'm talking soil, in general, and more specifically, conventionally farmed soil.  Also note that I specify CORRECTLY made compost.  Please don't include putrefying organic matter in the category of compost. 

Making compost on-site is better than buying compost from three states away, because the species in the compost will be site-selected.  Adding in a handful of HEALTHY soil from your own land is good, and it is something that Ron Stewart would always do.  How I wish Ron were still with us.  Maybe we should name that  process of adding healthy site-soil to a tea brew after Ron. 

Anyway, soil doesn't have the diversity that compost has, unless you add diverse  organic matter to the soil.  So some tropical soils have huge diversity, if there are 50 to 60 species of trees per acre, plus three to four layers of understory plants below that canopy. 

That kind of diversity just doesn't happen in conventional ag fields......

Can we culture this kind of diverse microbial community in the laboratory?   There is NO set of culture media that ANY human being knows that will grow more than the merest miniscule of all the species present in any soil, or any compost.  Humans have named only 5,000 species of bacteria, less than that of fungi.  Current DNA anlysis suggests that there may be millions of species of bacteria in the world, and tens of thousands of species in any gram of soil.  We can culture, or grow, only a drop in the bucket of the enormous number of species of bacteria and fungi that exist in any soil. 

When we limit growth conditions, we limit the species that can and will grow.  So, plate cultures are laughable when it comes to determining species diversity, and whether it is actually adequate or not. 

Compost has a wider set of conditions and food resources for microbial growth than any culture medium people can put together.  So compost is a great way to grow a huge set of the desired species.  But even there, we don't get ALL the species possible.  Making compost that is started at different times of the year (and therefore has different starting foods in the mix), and adding compost made at different times of the year, will continue to expand the diversity present in the soil you add the compost to.  So, keep adding.......

Maximize diversity.  Let the plant feed the organisms it needs to protect the root and foliar surfaces. 

We can't pretend that we know, or can even begin, today, to name all the species that a single plant needs, much less in different soils, or climates.  Will we be able to do that someday?  Maybe.  Need those molecular methods.  At a cost that growers can afford.  Molecular biology is the only hope for figuring out all the species of bacteria and fungi in a soil, or compost.  DNA analysis needs to be married with RNA analysis, and activity assessment.

Don't ask that of culture methods.  Plate counts just don't make it.  Even a range of culture media just don't allow growth of the diversity needed.

Hope this helps!  Hope I hit the important points that you were asking.  If not, please continue the conversation.

Elaine Ingham
President, Soil Foodweb Inc.
www.soilfoodweb.com
SFI Oregon, USA
SFI Australia
SFI New York
SFI Europe
SFI New Zealand

"Hope is not a feeling. It is not the belief that things will turn out well, but the conviction that what we are doing makes sense, no matter how things turn out."   --  Vaclav Havel, former President of the Czech Republic


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