From: "Lawrence F. London, Jr." <lflondon@mindspring.com>
To: permaculture
Subject: Re: Water Ponding/Management
Date: Sun, 23 Dec 2001 13:12:01 -0500
On Sun, 23 Dec 2001 16:21:58 +0100, "keller" <ak.and.ak@on-line.de>
wrote:
>If you draw lines on the map that run parallel to this key line, you will
>notice that above the key line, the distance of these lines from the next
>higher contour line will increase (because of the divergence). Below the key
>line, these lines are going to cross the next lower contour line (because of
>the convergence). This means that theses lines are actually going _down_
>from the middle of the valley. They conect points higher up on the valley
>bottom with points lower down on the ridge. (see Figure 9 on page 46 in
>"Water for every farm, Ken Yeomans Keyline Plan" - I think that picture is
>also in Mollison's Designer's Manual, but I am not sure. I have just sent my
>last copy to Cameroon, and the new one has not yet arrived. Maybe somebody
>can check.) If you plow with a chisel plow along such lines, water would
>flow allong the furrows from the valley to the ridge. In contrast to this,
>normally water will flow down into the valley on paths perpendicular to the
>contour lines.
The Yeomans Keyline plow system, to my way of thinking (and I have
used the famous Soil Saver) is the best soil conditioning tractor (or
horse/mule) drawn implement in existence, bar none. Have a look at the
website for this product. Amazing.
>Further down below the keyline, if you continue to plow parallel to the
>keyline, the slope of the furrows will become too steep. You must then
>select a new contour line as a guide line and plow parallel to it. The key
>line is the highest line that can be used like this.
>
>If you plow this way, water will spread evenly over the whole area instead
>of being concentrated in the middle of the valey. Because of the furrows, it
>will also penetrate much deeper into the ground. More water will be stored
>in the soil instead of leaving your farm quickly. Plant roots will reach
>deeper, thus bringing organic matter further down. In subsequent years, you
>can repeat this and plow a bit deeper each time. According to Yeomans, this
>way subsoil can be turned into top soil relatively quickly.
>
>In any case, get a copy of that book (or CD). May be the best investment in
>your lifetime. Ken Yeomans is also working as a consultant, not cheap, but
>probably well invested money (see his web site).
Thanks for this wonderful explanation of keylines, Andreas. The
keyline principle of water management and soil tilth building is
earthshaking in importance.