Substrate experiment by Stephen Pushak (forwarded mail)

[Paul Krombholz <krombhol at teclink_net>]

Stephen Pushak asked me to forward this to APD:

In as far as the substrate growth comparison is concerned, all of the plants
in the tank which had peat added to some of the pots are doing markedly
better than those in the tank which had no peat at all. I can't tell if
there is any difference between growth of pots with more or less clay or
peat however, as anticipated, those pots which had added lime & bone meal
(Ca, Mg, P) mixed in, there is better growth than those pots without even
though the pots all had equal access to any nutrients which would leak into
the water column. To me this signifies that there is a benefit to providing
phosphorous through the substrate especially where peat & clay are used to
help sequester it. Peat seems to have a very beneficial effect which is not
confined to the pots which had peat but helps those plants in pots with only
sand and grew in the tanks with peat in other pots. The peat benefits were
distributed through the water. I don't see any reason, not to use the peat
in the substrate and its easier to keep it submerged burred in the
substrate. Common sense suggests to me that it would be beneficial to mix
the sand, clay & peat together. I also mixed a very small amount of powdered
lime & bone meal, about 0.5 grams, for each pot, in with the dry materials
and then added a little water to make a thick mud which I let dry in the
pots prior to planting. I hope the drying well help to sequester some of the
nutrients onto the peat & clay.

-- 
Paul Krombholz in central Mississippi, expecting temps in the teens 
by tomorrow night.