[Terrapreta] Charcoal is hydrophobic

[Sean K. Barry]

Hi Brian,

Charcoal IS hydrophobic.  But, the pores in charcoal are not.  Some charcoal floats and eventually sinks ... the water goes into the pores of that charcoal, increasing its density.  Additionally, the effect of charcoal and of humic acid amendments to soil is that these enhance the health and populations of soil microbiology.  These increased numbers and activity of (living) microbes is where water is held in the soil.  The water becomes part of the "living" in the soil.  The hyphae of mycorrhizal fungi hold water, for instance.  Cellular cytoplasm contains a lot of water.  Soil microbes are hydrophilic.

Regards,

SKB
  ----- Original Message ----- 
  From: Brian Hans<mailto:bhans at earthmimic.com> 
  To: Terrapreta at bioenergylists.org<mailto:Terrapreta at bioenergylists.org> 
  Sent: Saturday, November 03, 2007 6:42 AM
  Subject: [Terrapreta] Charcoal is hydrophobic


  Hi group,

  Say... Something that has been bothering me for a while now. Humic acid and charcoal are both hydrophobic. Yet, I am constantly reading about how humic acid (and charcoal) holds soil moisture. 

  Here is a study<http://www.turfgrasstrends.com/turfgrasstrends/Soil/Do-Humic-Substances-Bolster-Water-and-Nutrient-Ava/ArticleStandard/Article/detail/420498?contextCategoryId=1413> talking about this aspect of humic acid. I was not able to find a study that specifically talks about charcoal but I am assuming that the same hold. This actually makes alot of sense from a chemistry point of view.

  I personally have not conducted a formal study for myself but have handled enough charcoal and humic acids to believe that adding charcoal/humic acid to a soil will actually decrease the water holding capacity of the soil. 

  Im looking for some comments...

  Brian Hans
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