Skip to Content.
Sympa Menu

permaculture - Re: [permaculture] Dry farming [Fwd: [SANET-MG] soil's influence on transpiration]

permaculture@lists.ibiblio.org

Subject: permaculture

List archive

Chronological Thread  
  • From: Dieter Brand <diebrand@yahoo.com>
  • To: permaculture <permaculture@lists.ibiblio.org>
  • Subject: Re: [permaculture] Dry farming [Fwd: [SANET-MG] soil's influence on transpiration]
  • Date: Sun, 13 Jan 2008 02:10:16 -0800 (PST)

Lawrence,

I'm not subscribed to SANET. Would you mind also forwarding the
replies Edna receives to her question, as this is of particular interest
to me. Thanks for the trouble.

Dieter Brand
Portugal

Krystle Chung <learning@selfmadefarmer.com> wrote:
Lawrence,

If you haven't already, check out "The Drought Myth" by William A. Albrecht.
Here's a link to the two page PDF:

http://www.acresusa.com/toolbox/reprints/droughtmyth_nov00.pdf

It discusses the relationship between soil fertility and the effect of
drought on the frequency and severity of crop failures. I'm in NM at the
time and I found it very interesting; you might, as well.

Best,

Krystle
http://www.selfmadefarmer.wordpress.com

On Jan 12, 2008 9:55 PM, Lawrence F. London, Jr. wrote:

> -------- Original Message --------
> Subject: [SANET-MG] soil's influence on transpiration
> Date: Sat, 12 Jan 2008 17:05:03 -0700
> From: Edna Weigel
> To: SANET-MG@LISTS.IFAS.UFL.EDU
>
> A friend convinced me to read John Jeavon's "How to Grow More
> Vegetables..." It's extensive bibliography includes John A. Widtsoe's
> 1919
> "Dry Farming." On http://books.google.com/books I found Widtsoe's 1910
> "Dry Farming: a System of Agricultures Under a Low Rainfall" in free
> downloadable .pdf format which I found very interesting.
> I had always regarded transpired water as something over which I had no
> control if I wanted to grow a particular crop. However, Widtsoe quotes
> study after study in which fertilized soils or well-cultivated soils or
> previously summer fallowed soils produce on the order of twice as much dry
> matter per unit of water transpired as controls. That's impressive and
> especially important for growers like me in arid lands with falling water
> tables! There are brief hints that the addition of (as sodium nitrate) or
> formation of nitrates (enhanced by cultivation) makes the difference.
> These questions come to mind:
> 1) Have these observations from a century ago stood the test of time?
> (Enough studies were quoted to convince me the effects were real.)
> 2) If the answer to #1 is affirmative, why, in these days of global
> warming
> and drought and overdrafted aquifers and no-till methods is this
> information
> not more widely known? (I can't believe I'm the last person to learn
> this.)
> Could this relate to the cheapness of chemical fertilizers?
> 3) Could the numerous anecdotal stories (plus some careful experiments)
> showing the value--especially in drought conditions--of compost and other
> soil organic matter relate to the form (nitrate vs. ammonium) of nitrogen
> in
> the soil with or without added compost?
> My understanding of the chemistry of nitrogen compounds in the soil is
> sketchy, but it passes my common sense test that an aerated soil would
> tend
> to have more nitrate relative to ammonium ions when compared to a compact
> or
> water-logged soil. I don't have a feel for the effect of organic matter
> on
> the nitrate/ammonium balance. It also passes my common sense test that
> plants will transpire more water (until they get enough nutrients to carry
> on their life processes) if the water they take up from the soil doesn't
> contain adequate amounts of nutrients.
> I hope one or more SANETer(s) can enlighten me on transpiration and
> ways
> of maximizing crops while minimizing water loss.
> Regards,
> Edna
>
>
> _______________________________________________
> permaculture mailing list
> permaculture@lists.ibiblio.org
> Subscribe or unsubscribe here:
> http://lists.ibiblio.org/mailman/listinfo/permaculture
> Google command to search archives:
> site:https://lists.ibiblio.org/sympa/arc/permaculture searchstring
>
>
>
_______________________________________________
permaculture mailing list
permaculture@lists.ibiblio.org
Subscribe or unsubscribe here:
http://lists.ibiblio.org/mailman/listinfo/permaculture
Google command to search archives:
site:https://lists.ibiblio.org/sympa/arc/permaculture searchstring





---------------------------------
Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it
now.




Archive powered by MHonArc 2.6.24.

Top of Page