In article
,
VickyN wrote:
The cost in buying fertiliser and applying it is not always justified by
even the short-term returns, that is it is applied in excess of the
optimum
in some cases for reasons other than being demonstrated to be cost
effective.
The Omnivore's Dilemma: A Natural History of Four Meals
by Michael Pollan
http://www.amazon.com/Omnivores-Dile...als/dp/0143038
583/ref=pd_bbs_1?ie=UTF8&s=books&qid=1206815576&sr=1-1
(Available at a library near you, as long as they remain open.)
p.45 - 46
it takes more than a calorie of fossil fuel energy to produce a calorie
of food; before the advent of chemical fertilizer [a] farm produced more
than two calories of food energy for every calorie of energy invested.
or
Fossil Fuel and Energy Use, sustainable food - The Issues - Sustainable Table
A 2002 study from the John Hopkins Bloomberg School of Public Health
estimated that, using our current system, three calories of energy were
needed to create one calorie of edible food. And that was on average.
Some foods take far more, for instance grain-fed beef, which requires
thirty-five calories for every calorie of beef produced. x What¹s more,
the John Hopkins study didn¹t include the energy used in processing and
transporting food. Studies that do estimate that it takes an average of
seven to ten calories of input energy to produce one calorie of food.xi
OTOH I know of no analysis that shows we could feed the
world's
population by organic methods.
http://agroeco.org/doc/organic_feed_world.pdf
"Conversion to small organic farms therefore, would lead to sizeable
increases of food production worldwide. Only organic methods can help
small family farms survive, increase farm productivity, repair decades
of environmental damage and knit communities into smaller, more
sustainable distribution networks * all leading to improved food
security around the world."
- Christos Vasilikiotis, Ph.D.
University of California, Berkeley
There may be some focus on this issue
over
the next few decades as sources of mineral phosphorus compound become
exhausted and the cost of nitrogen fixing rises with energy costs.
I'm not sure what exactly you're getting at here. How is the cost of
buying fertiliser not justified by the short term returns? I also don't
understand your take on phosphorus as there is plenty sitting in soils
all over the world already.
http://westernfarmpress.com/manageme...al-phosphorus-
shortage
Experts fear critical phosphorus shortage
Jim Langcuster, Auburn University
Oct. 19, 2010 3:34pm
³There are estimates we have as little as 50 years left in the current
phosphate mines,² says Charles Mitchell, an Alabama Cooperative
Extension System agronomist and Auburn university professor of agronomy."
- Billy