Full Paper


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7 responses to “Full Paper

  1. Pingback: The Art of Composting | Creative Intelligence

  2. James I enjoyed your presentation and had several takeaways that will help me improve my compost making process. You did indicate that soil amendments were not necessary and that good soil biology would find and make available those minerals. You also indicated that typical soil lab tests are inaccurate measures of mineralization.. And that they don’t account for how soil biology obtain these minerals. If this is true, could you provide additional resources that show how microbes find minerals that are invisible by our standard soil lab tests? Are there ways to measure or test how microbes find these invisible minerals and make them available? Maybe we are looking the wrong way? All experts in gardening/crop growing that I have studied use some form of mineralization.
    Here is a link to soil test procedures from the lab I use (http://www.loganlabs.com/testing-procedures.html).

    • Thanks Tony, glad there were some good takeaways for you! I’m pretty sure I understand your questions.

      Any standard soil chemistry textbook would serve to document that what is reported on standard soil chemistry tests are only small portion of the the total pool of nutrients present in soil. “Environmental Soil Chemistry” by Donald Sparks is one in particular. So, “total soluble” nutrient levels are what are usually determined to be the nutrients available to plants, whereas “total exchangeable” levels, or “base saturation”, are much higher – but not considered plant-available. A decent calcium in the exchangeable pool is 3000 ppm, while the soluble pool will only be 100 ppm. So agronomists, only looking at that 100ppm soluble pool would say “obviously you need to add calcium, or else your plant won’t have enough.” I am quoting Elaine Ingham directly by saying “biology (soil organisms) will convert all the calcium in the exchangeable pool into soluble, if the correct biology (organisms) is present.”

      So yes, you understood me correctly when I said adding mineral amendments are not needed IF you have a healthy soil food web to make the “exchangeable pools” plant-available. Only four exchangeable nutrients are usually discussed on a soil chemistry test (calcium, magnesium, potassium and sodium), although all nutrients have exchangeable elements.

      So what I need to do is get some data for you that shows how the organisms make the exchangeable pool plant-available, and at what rates. That’s what you really what to know, if I understand your question

  3. Correct James.. 1. Data that shows microbes can make the exchangeable pool plant available.. 2. Is there a way to measure what is in the exchangeable pools? 3. IF the microbes tap into the exchangeable pools and take away Molybdenum, for example, for plant availability, How is this mineral eventually replenished? I know the plants send down sugars as a form of photosynthesis into the root ball and feed the microbes.. Do microbes have a role in creation of minerals? What process adds mineralization to the exchangeable pools?

  4. You’re asking great questions, and really in-depth questions. I can only answer a few of them well.

    The total mineral pools are constantly replenished from the underlying parent material of bedrock. Microbes, mostly bacteria and fungi work to break it down and have been doing so for billions of years, accounting for an ongoing and nearly endless supply of minerals. “Oxalic acid crystals are formed by the mycelia of many fungi. Oxalic acid mineralizes rock by combining with calcium and many other minerals to form oxalates. Calcium oxalate sequesters two carbon dioxide molecules. Carbon-rich mushroom mycelia unfold into complex food webs, crumbling rocks as they grow, creating dynamic soils that support diverse populations of organisms.” -from Paul Stamet’s book, Mycelium Running.

    David Coleman and colleagues have done a lot of research on the subject of nutrient pools and the effects of soil organsms. I was only able to find one of his earlier research papers on the subject, “Biological Strategies of Nutrient Cycling in Soil Systems” where he discusses the presence of large exchangeable pools.

    Apparently there’s multitutes of studies most any issue of the following journals, for some reason I’m terrible at finding what I’m looking for in science journals:
    Biology, Fertility of Soils, or Applied Soil Ecology

    The first paper on the topic with data showing microbes can make the exchangeable pool plant available was Ingham et al, 1986, the Ecological Monograph. That’s “Russel Ingham, et. al.” not Elaine. I don’t have it on hand but I asked Elaine to send it to me when she returns from a trip in a couple weeks.

  5. Thank you again for your follow up.. I have a much better understanding and will check out your references.. Looking forward to Dr. Ingham’s material.. I was inspired to look into my compost pile this week and was pleased to find some earthworms down there even in this frigid cold.. That tells me I got some good thermal activity going on.. Which I probably disturbed..

  6. Here’s the link to the paper by Ingham, R.E., J.A. Trofymow, E.R. Ingham and D.C. Coleman. (1985). Interactions of bacteria, fungi and their nematode grazers: Effects on nutrient cycling and plant growth.
    The full article is available as a read only on jstor: http://www.jstor.org/discover/10.2307/1942528?uid=3739832&uid=2&uid=4&uid=3739256&sid=21103491916123

    Also, a google scholar search of “Cynthia Cambardella” or “Dave Coleman” and “nutrient cycling” will older and newer research on all this stuff. Good luck and happy growing!

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