[Terrapreta] Terra Preta - not just about charcoal in soil

[Sean K. Barry]

Hi Jon,

I know that observation and experimentation are the keys to advancing any scientific hypothesis into a scientific theory.  We have two independent observations of this same phenomenon, Jon!  One from your farmer friend and another by Larry Williams view on what he saw in his beets.  I think this is great news!  This could make for a really useful scientific investigation.  The consensus observation is that charcoal amendments alone to soil seems to reduce nitrogen in the soil.

Were these observations of actual measured soil nitrogen losses or are they observations of the effect of nitrogen deficiency in the plants, i.e. did Larry think the beets looked like they did not get enough nitrogen or did he see a measured drop in soil nitrogen content?  It might be useful to make a nutrient assay of some sort on the soils to determine what the soil nitrogen levels are now.  If there were any un-amended (with charcoal) soil controls, then they could also be measured for a nitrogen concentration baseline.  Is it possible that what has occurred is that the charcoal amendments have made the nitrogen less available to the plants (but it is still in the soil)?

Your hypothesis, if I read you correctly, is that the soils are now nitrogen deficient and this is due to a loss of the equilibrium or natural balance between nitrogen and carbon concentrations in the soil, caused by the carbon increase that came with the charcoal?  Would you be willing to ask any of the soil scientists at your AgLabs if they could propose any possible mechanisms for this?  Maybe it could be a testable suggestion?  Maybe we could devise an experiment or a test, which we could ask your farmer friend and/or Larry Williams to perform or let someone perform on their fields?

I think that for the development of any theory about how or why charcoal amendments reduce nitrogen levels or available nitrogen, then it would need to come by way of an experimental validation of such a proposed mechanism, with results that would be predictable, and repeated at least once, the same result from the same test, in two different fields.  The proposed mechanism would imply some expected results.  Can we see the cause leading to the effect?

I could see, certainly, that if measured nitrogen is now deficient in a fields' soils, which had been solely amended with charcoal, that adding nitrogen (from any source) would increase the nitrogen concentrations, at least temporarily.  If your hypothesis is correct, then would you think that the restored nitrogen concentrations would remain restored?  Maybe the charcoal causes the nitrogen deficiency and it would remove more nitrogen over time if more nitrogen were to be added?

My point is, that consensus "observations" are really just a great starting point for determining what is occurring here.  What follows is really the meat of scientific work.  From these observations, can we see the cause leading to the effect?  If we can, then we are developing a theory for what is occurring.  If any hypothesis is correct, then some experimental results should be predictable and these will validate the cause leading to the effect premise.

We cannot act on mere "observations" and call it a theory, until we can expound from those "observations" to predict some expected experimental results, and then show repeatable, well-documented, reoccurrence of those experiments and results.

Before I repeat myself again...

Regards,

SKB
  ----- Original Message ----- 
  From: Jon C. Frank<mailto:jon.frank at aglabs.com> 
  To: Terrapreta<mailto:terrapreta at bioenergylists.org> 
  Sent: Tuesday, October 02, 2007 5:26 PM
  Subject: Re: [Terrapreta] Terra Preta - not just about charcoal in soil


  The reason I mentioned nitrogen deficiency is because that is what the farmer observed and told us when he used charcoal.  We can learn a lot form people who observe nature.

  How can charcoal lead to an N deficiency?  Not 100% on that but I suspect the soil is always trying to come to an equilibrium point in regards to Carbon vs. Nitrogen and by adding more carbon the soil needs more nitrogen to reach the equilibrium point.  Just my theory.  No Sean I won't waste my time trying to validate or invalidate the theory.

  To validate all you need to do is look for a nitrogen deficiency.  Further validation may come from analyzing tissue for nitrogen.  The easiest way to do that is to use a field meter such as:
  http://www.specmeters.com/Chlorophyll_Meters/Minolta_SPAD_502_Meter.html<http://www.specmeters.com/Chlorophyll_Meters/Minolta_SPAD_502_Meter.html>

  To prevent this N deficiency put on more nitrogen when using charcoal.  Not a politically correct answer but it is a great answer when you are a consultant and people depend on you to make help them get a good crop.

  Jon
    -----Original Message-----
    From: Sean K. Barry [mailto:sean.barry at juno.com]
    Sent: Monday, October 01, 2007 11:49 AM
    To: Terrapreta; Jon C. Frank
    Subject: Re: [Terrapreta] Terra Preta - not just about charcoal in soil


    Hi Jon,

    How could charcoal lead to a nitrogen shortage (in soil is where I presume you are speaking of)?  Can you suggest any ways to validate this?  Can you suggest any ways to prevent this?

    Regards,

    SKB
      ----- Original Message ----- 
      From: Jon C. Frank<mailto:jon.frank at aglabs.com> 
      To: Terrapreta<mailto:terrapreta at bioenergylists.org> 
      Sent: Monday, October 01, 2007 11:09 AM
      Subject: Re: [Terrapreta] Terra Preta - not just about charcoal in soil


      Just adding charcoal may lead to a nitrogen shortage.

      Jon
      www.aglabs.com<http://www.aglabs.com/>

        -----Original Message-----
        From: terrapreta-bounces at bioenergylists.org<mailto:terrapreta-bounces at bioenergylists.org> [mailto:terrapreta-bounces at bioenergylists.org]On Behalf Of Sean K. Barry
        Sent: Monday, October 01, 2007 10:12 AM
        To: Robert Flanagan; Kevin Chisholm
        Cc: terrapreta at bioenergylists.org
        Subject: Re: [Terrapreta] Terra Preta - not just about charcoal in soil


        Hi Kevin, Robert,

        Good questions, Kevin!  Right on point as I see it.  I would maybe add one more request, Robert.  4. Could we see if adding just charcoal made from the stover on a plot continues to show soil with "... a profound effect on plant development with no other soil fertility program".  You must be careful that only charcoal made from the wastes on the plot is used.  Adding more rice hull charcoal, for instance, would add some fertilizing nutrients that were taken from the soil that the rice grew in.  Adding new rice hull charcoal would not show the benefits of charcoal alone in the soil.

        As I see it, the contention in recent discussions has been that charcoal made from the plant crop wastes alone (corn stover) on an agricultural field, when applied to that field (alone, up to 10 or 50 repeated times) is all that is required to increase or maintain the soil fertility.  My reading is that this is NOT TRUE.  I do not see that the nutrient content can be maintained, as each harvest of the corn cobs will deplete the nutrients and the charred stover will add nothing new beyond what was there when the crop sprouted.

        Adding anything else would not reveal the value of charcoal in the soil.

        Regards,

        SKB
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