Re: manure-soil mix
>From: Elizabeth Worobel <eworobe at cc_UManitoba.CA>
>Date: Thu, 1 Feb 1996 07:24:04 -0600 (CST)
>Subject: Re: peat as substrate
>Dont add composted manure! The organic matter is way too high ...
>generally a soil substrate should not have more than 20% organic matter
>or the macrophyte growth decreases. Peat is not a problem, however, since
>the organic matter is 'refractive', that is , it is not easily oxidized.
>One of the main benefits of a soil substrate is that it is anaerobic ...
>this solubilizes iron, phosphorus and converts N-NO3 to N-NH4 which is
>preferred by most aquatic plants. You do not want these minerals leaching
>back into the water, in fact a heating coil works the other way by
>bringing water into the soil (or so I'ver read).
>The best substrate for growing aquatic plants is a silt or sandy loam
>with about 10 to 20% organic matter. The trick is to find some that is not
>contaminated with chemicals.
I have had very good growth with crypts and many other plants in a 50:50
mixture of cow manure and topsoil that I mix together and compost in a
plastic sweater box for three weeks before using. During the composting
period the easily broken-down organic matter is broken down, and only the
more resistant stuff remains. The biological oxygen demand of the remaining
organic matter is not so great as to cause any problems for most aquatic
plants because they have an extensive air channel system that carries
oxygen by diffusion to their roots. Some of the Aponogetons, especially
lace plants don't like that much organic matter, but everything else does
just fine for me.
Oh yes, I almost forgot to add that Anubias nana also should be grown in
low organic content soil. or, better yet, gravel with a little soil at the
bottom. A. nana has roots with very tiny air channels, and these roots
seem more adapted to hold the plants to rocks in a stream than to penetrate
an anaerobic mud. They are able to attach to stones like the modified
rootlets that hold English ivy to walls or tree trunks.
Paul Krombholz Tougaloo College, Tougaloo, MS 39174
Where it almost never snows, but I wish it would.