Re: [compost_tea] low phosphate?
Hi Lynton -
I'm not really clear on what the reply from the person was, because the
following is not a reply that makes any sense.
Also total P (Bray-2, as done by agri-energy www.agrienergy.net) is
very low (77kg/ha - compared to 620 kg/ha 'desired').--->
Do they understand what a Bray -2 extraction actually measures? It does NOT
give total P. Not by a long shot.
Total P has to be extracted using a strong acid, like sulfuric, or
hydrochloric. A Bray 2 only gives tiny proportion of the P that is actually present in
the soil.
A huge number of species of bacteria and fungi can extract P from the soil.
All those mycorrhizal fungi are great at doing this in addition. They can
access literally thousands of micrograms of P that a Bray 2 will not even begin
to extract, if you give the organisms the chance. Just like people, however,
soil organisms need air, water, food and housing.
Supply these things, and what is extractable by a Bray 2 will suddenly
increase by many fold.
Elaine R. Ingham
Soil Foodweb Inc., Corvallis, Oregon
Soil Foodweb Inc., Port Jefferson, New York
Soil Foodweb Institute, Lismore Australia
Soil Foodweb Institue Cambridge, New Zealand
Soil Foodweb Inc., Hilversum, The Netherlands
Laboratorios de Soil Foodweb, Culiacan, Mexico
Soil Foodweb Inc., Jerome, Idaho
Received on Thu Sep 16 2004 - 21:53:44 EDT
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