Date: Fri,  8 May 1992 16:32:41 -0400 (EDT)
From: "Joanne M. Karohl" <jk13+@andrew.cmu.edu>
Subject: Re: clay soil, tilled too wet

Hi!  Here is what I have been advised so far:

Paul Harvey, as you have probably read, believes devoutly in ground fir
bark to amend clay soil in the long run, and I asked him to elaborate on
what that substance was (specifically I asked if it was the coarse
shaggy stuff sold with the wood chip mulches).  He responded:

>It sounds like you found it. It is a course material, that has something to
>do with the way it works in breaking up clay. It is called redwood mulch or
>douglas fir mulch or ground fir mulch. The pieces are no bigger than say 1/2
>inch and include many fine sawdust type particles. It also makes an excellent
>mulch, by the way. Don't use woodchips or sawdust, these are not fir
bark. >Don't
>use the big chunk bark mixes, these are for decorative mulches. Ground fir
>bark looks like shreded bark off of a fir tree. It does not look like other
>amendments, it holds very little water and by itself would make a poor soil.
>But it is usually low cost and it works like magic in clay soils and makes a
>great mulch on the top. Another option that I've been told works well is rice
>hulls. Leaf mulch is not bad either, but it doesn't work as well and you'll
>have to add more every year as it decomposes in the soil and if you get it's
>concentration above 25%, you are bound to start having the problems you get
>with a high organic soil, mostly too many soil bugs. The fix for alkaline soil
>is sulfur, and check your water also. If it is alkaline, you can correct it
>with swiming pool acid or use rainwater.

Then Dick Rawson sent me the following:

>I'd say to water it heavily, enough to reach all through the clods,
>and then let it dry enough.  Our clay soil here passes through a
>delightful stage between sticky and bricky; then, it falls apart
>most easily (as easy as it will get).  Breaking the stuff while
>dry has to be much more work, and wouldn't you be compressing the
>damper sub-surface soil?

I assume he means to dampen the stuff enough that it crumbles, but not
enough that it is sticky (I asked if that was what he meant, but
haven't heard back yet.)  If you find anything else out, let me know,
and I will send you anything else I learn.  Good luck!
   
Joanne