[Terrapreta] alkaline soils

Sean K. Barry sean.barry at juno.com
Tue May 22 23:56:49 CDT 2007


Hi Randy,

You really did a fantastic job in the write up of your experiment!  I like your analysis and your caveats.  I like the structure of the report (Introduction and Experimental Procedures, Results, Discussion, and Summary).  I am very impressed (that isn't really saying anything, because I'm probably not really qualified as an experimental critic, so don't let it go to your head!).  Please do accept my compliments, though, on a job very well done.  I hope we hear from you a lot more in this venue.

SKB

  ----- Original Message ----- 
  From: Randy Black<mailto:rblack at hillcity.k12.sd.us> 
  To: terrapreta at bioenergylists.org<mailto:terrapreta at bioenergylists.org> 
  Sent: Wednesday, May 16, 2007 12:57 PM
  Subject: Re: [Terrapreta] alkaline soils


  Michael, You have been following all my posts on pine needle biochar.
  For the acid loving plants you may need that or some other source
  material that was acidic to start with. From my research the more
  bio-oil you have in the char the more acidic and from "The ph of Pine
  Needle Bio-Char" the pure "bio-oil" could reduce alkaline water at a 64
  to 1 ratio. Also the more partial the pine needle char the higher the
  acidic effects.

  Now one thing that others have brought up is the natural buffering
  capacity of soil. That is how it resists ph change. As I mention I don't
  have any field data on that or how long the bio-oil acidic effect would
  last in the soil. This definitely needs more research.

  RB

  The ph of Pine Needle Biochar by Randy Black 

  Note: This experiment was done in my kitchen using a blender, small
  measuring cup, and litmus paper. Do not confuse this with a real
  laboratory science experiment or a real science journal article. I tried
  to be as exact as I could but the variability of the pine needle
  biochar, the charring process, and my measuring and material processing
  make the results a measure of generalized trends not specific facts. I
  encourage others to try this or other Terra Preta science experiments
  and report the results as there are huge areas of Terra Preta applied
  technology that we are only now experimenting with and understanding.

  Introduction and Experimental Procedures
  Pine needles are an acidic material and pine needle mulch has been used
  to lower the ph in soil. This investigation looks at the ph effects of
  pine needle biochar on water with ph levels of 7, 8, and 9. It also
  looks at pine needle char from across the combustion continuum of
  partial char to char and compares them with uncharred pine needles and
  an oil/water material collected from condensed pine needle smoke.
  Charcoal has the affect of increasing the ph in soil and this experiment
  investigates the ability of pine needle biochar to decrease the ph in
  soil. 

  The pine needles were charred in a small metal kiln at a low temperature
  for 6 hours. There was a high variability in the temperature as the heat
  source from burning wood in the bottom of the kiln was closer to the
  some of the pine needle material than other parts of the sample. The
  pine needles were separated by larger wood pieces from the burning pine
  wood (heat source), but were exposed to smoke from this source. It has
  been noted in previous burnings that this smoke leaves a thin coat of
  volatile oil on the sides of the kiln and material at the top of the
  kiln so it is presumed that the partial char pine needles also were
  coated with this oil and a small part of the ph results may be due to
  this oil.

  The pine needles were collected from the forest floor and were a
  combination of last years needles which were tan (70%), and previous
  year's needles which were tan to grey (30%). The needles maintained
  their structural integrity and were dry to the touch. One thing noted in
  this and in previous experiments with charring pine needles is that the
  smoke given off is much thicker than regular pine wood being charred and
  there is noticeably higher moisture content. This was evident by the
  condensation on the top of the kiln lid which was collected and is the
  "bio-oil" in this investigation. One interesting fact when charring pine
  needles is that when the oxygen is restricted to stop the burn unlike
  regular charcoal loads the mix continues to smolder at a low level until
  put out by water. This implies that the gases from the heated pine
  needles provide enough oxygen to continue the charring process. The pine
  needles in this study continued to smolder in these conditions for an
  additional 9 hours.

  When the mass of needles was removed from the kiln it was layered with
  partial char on top to charred pine needles on the bottom. The samples
  in these ph experiments are from these two layers and have the following
  characteristics. The partial char is a golden brown color, maintains the
  original pine needle structure, and is sticky wet to the touch due to
  the condensate from the pine needle pitch and burning wood. The pine
  needle char still looks like pine needles but is dry and can be easily
  crumbled into small pieces and powder. The variability of the pine
  needles across the combustion continuum and variability of the charring
  process temperatures and conditions makes the data of this study highly
  subjective and the results should be looked at as generalized trends not
  specific data points.

  All of the ratios in the following results are by volume not weight and
  further studies using weight ratios will need to be done to calibrate
  the ph reduction capacity of pine needle biochar. The processing of the
  material (dry unburnt pine needles, partial char, char, and bio-oil),
  and its effective surface area lends further uncertainty to these
  results and again these results are generalized trends not specific
  facts.

  The pine needle material was tested with distilled water (ph 7), tap
  water (ph 8), and water that had been soaking in pine charcoal (ph 9).
  The testing was done with litmus paper and read visually so the data is
  not exact figures but approximations of the ph affects of pine needle
  biochar.

  Results
  Experiment 1
  The four types of pine needle material are dry unburnt needles, partial
  pine needle biochar, charred pine needles, and bio-oil made from
  condensed pine needle smoke. In the first set of experiments each
  material was mixed with an equal volume of water stirred for 30 seconds
  and measured in the next 30 seconds. Data is given in ph of water
  followed by ph of the change.
  1. Dry unburnt pine needles with ph 7 water - 6.9 to 7 ph; ph 8
  water - 7 ph; ph 9 water - 8 ph.
  2. Partial pine needle char with ph 7 water - 6.4 ph; ph 8 water -
  6.5 ph; ph 9 water - 6.5 ph.
  3. Charred pine needles with ph 7 water - 7 ph; ph 8 water - 7.5
  ph; ph 9 water - 8.1 ph.
  4. Pine needle bio-oil with ph 7 water - 6 ph; ph 8 water - 6 ph;
  ph 9 water 6 ph.

  Experiment 2
  The following results are from charred pine needles in both ph 8 and ph
  9 water with readings taken at 1, 5, 10, and 20 minutes.
  1. In ph 8 water - 7.5 ph at 1 minute; 7.1 ph at 5, 10, and 15
  minutes.
  2. In ph 9 water - 8.1 ph at 1 minute; 7.8 ph at 5 minutes, 7.5 ph
  at both 10 and 20 minutes.

  Experiment 3
  The following experiment uses ph 8 water and charred pine needles in
  increasing ratios of  water to charred pine needles with readings taken
  at 1, 2, 5, and 10 minutes.
  1. Ratio 4 to 1; ph 7.4 at 1 minute; ph 7.1 at 2 minutes; ph 7 at
  both 5 and 10 minutes.
  2. Ratio 8 to 1; ph 7.6 at 1 minute; ph 7.3 at 2 minutes; ph 7.2 at
  both 5 and 10 minutes.
  3. Ratio 16 to 1; ph 7.9 at 1 and 2 minutes; ph 7.8 at both 5 and
  10 minutes.

  Experiment 4
  The following experiment used ph 9 water and bio-oil in increasing
  ratios of water to bio-oil. Measurements were taken at 1 minute.
  1. Ratio 4 to 1 ph 6
  2. Ratio 8 to 1 ph 6
  3. Ratio 16 to 1 ph 6
  4. Ratio 32 to1 ph 6.5
  5. Ratio 64  to 1 ph 7.1

  Discussion
  The results in Experiment 1 show that the acidic effects of pine needles
  rest mainly in the volatile oil/acids contained in pine needles as seen
  in the partial char and bio-oil results bringing the ph levels down to
  below 7. However pine needle char will bring the ph level of water down
  to towards the neutral level of ph 7 as seen in Experiments 2 and 3 with
  longer exposure. The difference between the ph affects of bio-oil and
  charred pine needle may be due to a chemical process versus and
  physical-chemical process as low temperature biochar does contain some
  of the parent materials properties as impurities with the char. More
  investigations are needed to identify what affects the high surface
  area, adsorption properties, and impurities in low temperature pine
  needle biochar have on modifying ph. Dry ground uncharred pine needles
  also lower the ph of water but take much more processing time and energy
  and do not have the adsorption properties or increased cation exchange
  capacity of char.

  The results of Experiment 4 show that a small amount of pine needle
  bio-oil can significantly reduce the ph of large amounts of water. At a
  ratio of 16 parts ph 9 water to 1 part bio-oil the ph was still reduced
  to 6 within one minute. At a large ratio of 64 to 1 the bio-oil still
  reduced the ph to 7.1. It is clear that the condensed pine needle smoke
  concentrated the acids in pine needles. Field investigations should also
  look into this bio-oil being applied back to pine char before use and if
  the adsorption properties and recalcitrance of char might make this a
  long term ph modifying soil amendment. 


  What affects partial char, char, and bio-oil would have on high ph soils
  would need to be field tested with a variety of soil under various
  condition and with differing percentages of pine needle biochar/bio-oil.
  Reducing the ph of water and reducing the ph of soils are two different
  processes and long term field testing is needed. Most likely the
  acidifying affects of the bio-oil and partial pine needle biochar would
  be temporary but due to the recalcitrance of charcoal, its high surface
  area, and adsorption properties, charred pine needles may be able to
  maintain soil at a ph level of 7 for much longer. 



  Summary
  The implications of pine needle biochar for Terra Preta research and
  charcoal enhanced soils are tremendous. First, we now have the ability
  to add char to soil that will reduce the ph level instead of increase it
  but still contribute the benefits of charcoal in soil using a common
  readily available material. This has implications for alkaline soils and
  to create soils for crops that need acidic conditions. Second, this
  demonstrates that we can tailor one of the chemical properties of
  biochar to match soil conditions based on the chemistry of the parent
  material. This means that Terra Preta science can be applied to a wide
  variety of soils and has the potential to be individualized to match
  soil ph conditions and crop ph ranges. Third, if we can do this with ph
  levels can Terra Preta science be applied to doing this with trace
  minerals for crop nutrients or for a chemical/mineral balance that may
  be selective in establishing a desirable specific microbial community.
  The physics and chemistry of pine needle biochar's ph affects are
  entirely different from what would be needed to add specific
  minerals/chemicals to soil but demonstrates that Terra Preta technology
  is much more than just adding charcoal to the soil and could
  revolutionize our ideas on soil and crop management.





  -----Original Message-----
  From: terrapreta-bounces at bioenergylists.org<mailto:terrapreta-bounces at bioenergylists.org>
  [mailto:terrapreta-bounces at bioenergylists.org] On Behalf Of
  terrapreta-request at bioenergylists.org<mailto:terrapreta-request at bioenergylists.org>
  Sent: Wednesday, May 16, 2007 11:00 AM
  To: terrapreta at bioenergylists.org<mailto:terrapreta at bioenergylists.org>
  Subject: Terrapreta Digest, Vol 4, Issue 143

  Send Terrapreta mailing list submissions to
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  Today's Topics:

     1. important correction (Christoph Steiner)
     2. Fwd: Scientific American Article on TP (jim mason)
     3. Re: Fwd: Scientific American Article on TP (Michael Bailes)
     4. Re: alkaline soils (Michael Bailes)


  ----------------------------------------------------------------------

  Message: 1
  Date: Wed, 16 May 2007 14:15:06 +0200 (CEST)
  From: "Christoph Steiner" <Christoph.Steiner at uni-bayreuth.de<mailto:Christoph.Steiner at uni-bayreuth.de>>
  Subject: [Terrapreta] important correction
  To: terrapreta at bioenergylists.org<mailto:terrapreta at bioenergylists.org>
  Message-ID:
  <60863.83.215.117.89.1179317706.squirrel at mail.uni-bayreuth.de<mailto:60863.83.215.117.89.1179317706.squirrel at mail.uni-bayreuth.de>>
  Content-Type: text/plain;charset=iso-8859-1

  Sorry it was my mistake: it is higher pH in Terra Preta soils!





  ------------------------------

  Message: 2
  Date: Wed, 16 May 2007 08:31:42 -0700
  From: "jim mason" <jimmason at whatiamupto.com<mailto:jimmason at whatiamupto.com>>
  Subject: [Terrapreta] Fwd: Scientific American Article on TP
  To: terrapreta <terrapreta at bioenergylists.org<mailto:terrapreta at bioenergylists.org>>
  Message-ID:
  <31a4f6f00705160831j1ee3cb1dx71255bb9fa3e55df at mail.gmail.com<mailto:31a4f6f00705160831j1ee3cb1dx71255bb9fa3e55df at mail.gmail.com>>
  Content-Type: text/plain; charset=ISO-8859-1; format=flowed

  TP seems to be moving into the mainstream media quite quickly.
  here's a major new one from scientific american.


  http://www.sciam.com/article.cfm?chanID=sa028&articleID=5670236C-E7F2-99<http://www.sciam.com/article.cfm?chanID=sa028&articleID=5670236C-E7F2-99>
  DF-3E2163B9FB144E40&pageNumber=1&catID=4



  -- 
  ------------------------------------------------------------------------
  --------
  jim mason
  website: www.whatiamupto.com<http://www.whatiamupto.com/>
  email: jimmason at whatiamupto.com<mailto:jimmason at whatiamupto.com>
  announce list: http://lists.spaceship.com/listinfo.cgi/icp-spaceship.com<http://lists.spaceship.com/listinfo.cgi/icp-spaceship.com>
  current project: mechabolic
  (http://whatiamupto.com/mechabolic/index.html<http://whatiamupto.com/mechabolic/index.html>)



  ------------------------------

  Message: 3
  Date: Thu, 17 May 2007 02:28:37 +1000
  From: "Michael Bailes" <michaelangelica at gmail.com<mailto:michaelangelica at gmail.com>>
  Subject: Re: [Terrapreta] Fwd: Scientific American Article on TP
  To: terrapreta <terrapreta at bioenergylists.org<mailto:terrapreta at bioenergylists.org>>
  Message-ID:
  <7dcba7be0705160928t3f31afd8v61a10c4f80404fed at mail.gmail.com<mailto:7dcba7be0705160928t3f31afd8v61a10c4f80404fed at mail.gmail.com>>
  Content-Type: text/plain; charset="iso-8859-1"

  It's a good article.

  It has already been posted to digg.com
  Please "digg" it - so it moves up the news hierarchy.

  Somebody has got to bloody notice Terra preta one day!
  m

  On 17/05/07, jim mason <jimmason at whatiamupto.com<mailto:jimmason at whatiamupto.com>> wrote:
  >
  > TP seems to be moving into the mainstream media quite quickly.
  > here's a major new one from scientific american.
  >
  >
  >
  >
  http://www.sciam.com/article.cfm?chanID=sa028&articleID=5670236C-E7F2-99<http://www.sciam.com/article.cfm?chanID=sa028&articleID=5670236C-E7F2-99>
  DF-3E2163B9FB144E40&pageNumber=1&catID=4
  >
  > -
  >
  >
  ------------------------------------------------------------------------
  --------
  > jim mason
  >
  >
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  Message: 4
  Date: Thu, 17 May 2007 02:37:28 +1000
  From: "Michael Bailes" <michaelangelica at gmail.com<mailto:michaelangelica at gmail.com>>
  Subject: Re: [Terrapreta] alkaline soils
  To: terrapreta <terrapreta at bioenergylists.org<mailto:terrapreta at bioenergylists.org>>
  Message-ID:
  <7dcba7be0705160937q3348dc74g37bc2aa020b3758f at mail.gmail.com<mailto:7dcba7be0705160937q3348dc74g37bc2aa020b3758f at mail.gmail.com>>
  Content-Type: text/plain; charset="iso-8859-1"

  I am trying to interest Oz nurserymen to trial some char in potting
  mixes.
  The first thing they are going to ask is "What will it do to the pH of
  my
  potting  mix."
   Especially when one nursery produces a zillion, acid loving, camellias.

  m

  On 16/05/07, Christoph Steiner <Christoph.Steiner at uni-bayreuth.de<mailto:Christoph.Steiner at uni-bayreuth.de>>
  wrote:
  >
  > I have my doubts that "Terra Preta" is the solution for all
  agricultural
  > constraints. Terra Preta was created to overcome the environmental
  > constraints in the Amazon. Alkaline soils are not among them, the
  opposite
  > is the case.
  > Ash and most charcoal are alkaline. Therefore I recommend being
  cautious.
  > But anyway it is very interesting to look what effect charcoal
  additions
  > to alkaline soils have. For my knowledge this was not studied yet and
  > alkalinity is a widespread problem.
  >
  > C. Steiner
  >
  >
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