David Yarrow, May 2010

Using Biochar in Soil

Preparation & Application

Biochar Preparation

Applying raw biochar to soil can inhibit plant growth one or two
years while microbes inhabit the char, form diversified, stable,
functional communities, and gather balanced mineral supplies.
Microbes also consume tar residues that inhibit water absorbtion.
Several weeks to a few months are needed to age char for
soil. Proper preparation can reduce this time to two weeks, and
reduce char volume needed for vigorous plant response. Four
simple steps assure rapid response, high yield and healthy plants.


Biochar’s first service to soil is water digestion, retention and
slow release from its sponge-like micropore matrix. Char must
soak up water to be an effective substrate for microbial cultures
and mobilize minerals for ion exchange with plant roots. To
moisten char, hydrophobic residues must be broken down and
removed—a task done mostly by microbes.

Spring Grower Gathering, David Yarrow April, 2010

Spring Grower Gathering

How to Make and Use Biochar

Sponsored by Transition Town Great Barrington (MA)


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