permaculture

[Chad Knepp <pyg@galatea.org>]

Right on!

Also interesting if you haven't already read it is 'Energy in
Agriculture: Lessons from the Sunshine Farm Project' published by The
Land Institute in November 2002.
<http://www.landinstitute.org/vnews/display.v/ART/2002/09/24/3dbeba6338ac3>

It documents a hands on study of biodiesel production.  Pertinent
quote:

  It will be a challenge to provide society with considerable energy
  from agriculture, let alone food, since the energy returns for
  various energy technologies have generally been greater than the
  above ratios for mixed crop and livestock farms.  Fossil fuels
  usually have ratios in the range of 10-30, and solar and wind
  technologies, typically 3-10, but renewable liquid or gaseous fuels
  from agricultural production, mostly 5 or less [37, 38]. Solar and
  wind technologies have greater power densities than energy crops and
  thus require less land area [24].


Cheers,
Chad

-- 
Chad Knepp
python -c 'import base64;print base64.decodestring("cHlnQGdhbGF0ZWEub3Jn")'


Marimike6@cs.com writes:
 > George Monbiot is a good source of intelligent analysis on a host of 
 > subjects. Here's his take on biofuels, and to me the numbers certainly 
 > support him.
 > 
 > http://www.monbiot.com/archives/2004/11/23/feeding-cars-not-people/
 > 
 > We have a first rate example in the midwestern US, where corn states make 
 > certain their congress members mandate the use of ethanol as a fuel 
 > additive. It 
 > costs more energy to grow, fertilize, transport, render (refine) and 
 > distribute the corn than it would to get the therms just from petroleum.
 > 
 > Sites like the following paint a glowing picture of the efficiency we're 
 > supposed to be gaining from the use of such "renewable" fuels
 > 
 > http://www.ethanolrfa.org/RFA_Fuel_Cell_White_Paper.PDF 
 > 
 > http://www.phillips66.com/energyanswers/savingfuel.htm 
 > 
 > but they fail to show the net energy loss from all the inputs involved in 
 > putting an ear of corn in your gas tank.
 > 
 > One major drawback:
 > 
 > Tremendous energy inputs are required to make commercial fertilizers, 
 > which 
 > are then transported and applied to the fields mechanically. There is a 
 > large 
 > net loss from nitrates poorly applied and superavailable in the wrong 
 > form. 
 > These excess nitrates get washed downstream from the Corn Belt into the 
 > Gulf of 
 > Mexico, creating the famous Dead Zone so fatal to shrimp populations 
 > offshore 
 > from the Mississippi River mouths. The nutrient-rich sediment loads that 
 > would 
 > normally be returned to the land in seasonal flooding are now managed by 
 > the 
 > Mississippi Authority and the Army Corps of Engineers at great expense to 
 > avoid 
 > flooding any land that doesn't want to be flooded. No more than a third of 
 > the sediment load is deposited in such useful places as the Atchafalaya 
 > Basin. 
 > 
 > The net result? The land that replenishes the lower Mississippi now gets 
 > washed out to be deposited on the steep slopes of the Gulf, creating the 
 > Dead 
 > Zone. The Mississippi Delta is losing ground rapidly, and is a shadow of 
 > what it 
 > was a couple of decades ago. We spend millions trying unsuccessfully to 
 > figure 
 > out how to combat this soil loss because we're afraid to take the 
 > necessary 
 > steps and flood the entire basin (odd details like New Orleans being right 
 > in 
 > the way).
 > 
 > http://www.oceanconservancy.org/site/PageServer?pagename=bpm_feature3_5
 > 
 > On the other end of the equation, soil loss in Iowa is so pronounced that 
 > farmsteads built in the 19th cebtury are now three feet higher than the 
 > surrounding fields-- so much Iowa soil has been lost.
 > 
 > Corn-based ethanol, in my opinion, is not a good solution to weaning 
 > ourselves from a dependence on fossil fuels. Other biofuels may be of 
 > local interest. 
 > In wholesale weed clearance projects, such as the freeing of waterways 
 > choked 
 > with hyacinth, it may be a useful treatment for a material that would 
 > otherwise be just a waste product.
 > 
 > And chopping wood is good for the soul. As well, it heats you twice-- in 
 > the 
 > chopping and in the burning. But as a macro-solution for human society, 
 > we'd 
 > have to cover the earth in fast-growing pulpwood just to satisfy our fuel 
 > needs. The numbers just aren't there, I'm afraid, for most large biofuel 
 > ventures.
 > _______________________________________________
 > permaculture mailing list
 > permaculture@lists.ibiblio.org
 > http://lists.ibiblio.org/mailman/listinfo/permaculture