permaculture

[<darren@permaculture.biz>]

G'day,

I trust that this greets you and all well.

Just to clarify that strictly speaking these rather familiar terraces are
not Keyline terraces at all - I have yet to see any of those as it is
largely impossible to maintain standing water converage over the whole
terrace because of the geography and geometry of Keyline as I will attempt
to briefly (!?!)and simply explain. They are just (unless you want them of
course!) rice terraces. Why not Keyline? If they were Keyline terraces then
all of the terraces would be parallel with each other - whereas clearly when
one follows contours then each contour is not parallel with that below or
above. 

To find determine the Keyline one must first locate the Keypoint of a
primary valley. The Keypoint of a primary valley is located where the
primary valley floor changes in profile from being convex to concave. One
marks this point in the centre line of the valley with a peg and then marks
a contour from it towards the adjacent primary ridges. The keyline of the
valley does not extend to the ridge itself but stays within the valley. The
horizontal line that is a marked contour will itself change from concave
(valley) to convex (ridge) at some point. These points of inflection mark
the end of the keyline of the valley. 

Plowing (non-inversion hopefully!) or making drains (by default because
running parallel with the Keyline will always ensure fall to the ridge)
above or below the keyline will ensure that runoff will always flow towards
the ridge - this evens out the flow of runoff across the foothills
landscape. On the ridge itself it one simply keeps a slight fall in the line
or keeps level (that's a personal preference in my opinion though strictly
speaking there will always be fall to the water divide line of a primary
ridge) - effectively reversing the drainage path than water naturally finds
by extending the residence time of runoff onto a ridge. 

Explaining all of this in mere text is onerous - which is what the other
authors of Keyline have obviously found - otherwise this very simple matter
would not be so often confused. The best way to get the "Keyline Design
Light Bulb Moment" is on the beach or in a sandpit or in the field with a
survey instrument, a tractor and a Yeomans Keyline Plow. 

A Keyline terrace as such is only possible on the Keyline contour itself as
it is the only "level" contour in Keyline practice. All of the parallel
lines above and below are falling across the actual elevational contours of
the landscape. 

Were Australia, the US and other countries to have adopted Keyline and its
Soil "Creation" methods as opposed to mere Soil "Conservation" then possibly
millions of hectares would have been included in higher value production,
particularly where machinery use is involved. Flying across Soil
Conservation farms all over the place clearly reveals the poor landuse
geometry of Soil Conservation and its practice of following the contours and
all of the consequent "stub" rows and missed areas that are largely absent
in properly designed Keyline properties where all of the rows are parallel
and evenly spaced across the farm landscape. Any wonder PA Yeomans used to
get so annoyed with Soil Conservation Authorities - they just didn't get it
or perhaps were in too deep to want to get it (quite apart from being
apparently satisfied with only conserving soil not creating it - also a bit
difficult when most farmers use anti-soil biocidal artificial fertilisers
and chemicals.)  

The same goes for swales while we are at it. I hardly ever use swales in my
designs for the above reasons. Furthermore I find Keyline plowing to be a
much better, more even and cost-effective means of getting groundwater
recharge, and where we incorporate so-called contour strip forests we get
the "contour strip runoff interception" that swales clearly afford. I can
get a what I think is a better effect using Keyline aligned mounds (planted
with trees) at eg. 4 - 8 - 16m spacings with Keyline plowed interrows
planted with production crops in between these mounded rows. 

Again this is perhaps difficult to explain without the benefit of photos, a
sandpit or a plow so I will quit here. I have amassed an array of images and
case studies and soon even video (plus our courses) to espouse the virtues
of the geography of Keyline over "simple" contour work. These will over time
be placed on our website to help continue the important Keyline Design
education process....  

Finally I have proprietory methods of revealing keypoints that students of
mine have clearly imprinted on their minds which perhaps for some may still
be causing some sleepless nights.... 
 

Yours and Growing,

 

Hooroo,

Darren Doherty
www.permaculture.biz 

Yahoo Voice: +1 310.237.6970
Cell: +1 805.455.8914

6 day Keyline Design Course - Finger Lakes Permaculture, Ithaca, NY, USA
18-23 June 2007
Bookings and info thru www.fingerlakespermaculture.org or
www.permaculture.biz 

6 day Keyline Design Course - Olba,(via Madrid-100kms)Spain - 
16-21 July 2007
Bookings and info thru antonio@permacultura-es.org or www.permaculture.biz 

No virus found in this outgoing message.
Checked by AVG Free Edition. 
Version: 7.5.467 / Virus Database: 269.6.5/792 - Release Date: 6/05/2007
9:01 PM