buffering up
T
he widespread use of calcium and magnesium supplements in the indoor gardening industry is an indication
that many growers have discovered the cation exchange
capacity (CEC) phenomenon in coco media. Growers are
observing deficiencies and trying to correct those deficiencies with calcium and magnesium supplements. This article
explores why these deficiencies happen and how adjusting
the cation exchange capacity, or buffering, the media corrects this problem.
Coco growing media has changed a lot in the last decade
or so. Previously, the majority of coco products were washed
to an EC of 1 or 1.6, and few products on the market were
buffered. Today, the higher-quality coco products are washed
multiple times and will have an EC of 0.5 or lower. They will
also be buffered in some way or another.
Coco Cation Exchange Capacity
Soil particles and organic matter have negative charges on
their surfaces that attract cations. The total of these negative
charges are collectively referred to
as the CEC. The CEC is significant in
growing media because it is a measure
of the quantity of nutrients the media
is able to hold on to before nutrients
start leaching out. Plants are able
to access the cations attached to the
cation exchange capacity.
“Soil particles and organic matter have negative charges
on their surfaces that attract cations. The total of these
negative charges are collectively referred to as the CEC.”
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Maximum Yield USA | April 2015