Originally Posted by bleusman
an article about the energy inefficiencies of organic farming.
To expand on bleusman's link - A study writen for the UK Ministry of Environment which concluded that: Organic Farming "No Better For the Environment."
It says that some crops were better others were worse, particularly: "Organic vine tomatoes require almost 10 times the amount of land needed for conventional tomatoes and nearly double the amount of energy."
Then there is this report
by Anthony Trewavas which appeared in the journal "Crop Protection." Other writing by the same author: GM is the Best Option We Have
and a presentation on Organic Food and Farming.
Also, here is a short piece by Dennis Avery asking Would Organic Farming Unleash A Billion Cattle On U.S. Wildlands?
As a vegetarian I find the possibility of increased cattle raising beyond concerning.
The Skeptic's Dictionary entry on organic food and farming
(which also talks about GMO)
One of the books that the Skeptic's Dictionary mentions is The March of Unreason
by Dick Taverne which includes chapters on "The Myth of Organic Farming," "The Case For GM Crops," and "The Case Against GM Crops."
On the pro-organic side is this report: Soil Fertility and Biodiversity in Organic Farming
which was the 21 year study that is most commonly cited as the proof that organic farming can feed the world. I had some issues with it when I read it shortly after it came out. First, the study actually showed that the organic agriculture had about 20 - 30% less yield. The difference in favour of of organic was that it used about 50% less energy per acre (because of the energy to create synthetic fertilizers and pesticides). However, if you take into account the decreased yield of the organics then the conventional crops only required less than 20% more energy per yield. So conventional requires more energy, organic more land. Also, the nutrients in the organic soil had decreased significantly (up to a 1/3 or even 1/2) for nitrogen potassium and phosphorus which means that soil was actually being depleted and eventually will require inputs outside of organic farming methods. This was one of the "miracles" of synthetic fertilizer in the first place. Before their inputs soil qualities in europe and parts of north america had decreased significantly over the preceding centuries.
So organic farming required less energy, but needed more land. To me that means that organic loses. However, when you add in the organic farm land was being depleted of nutrients it means that at some point in time they are going to need to use a lot of energy to replenish that land, probably meaning that in the long run organic farming needs far more land for no benefit what-so-ever.
Other studies have managed comparable yields, but don't make clear that they were using cover crops like legumes which means that about every 3rd growing season no crop was grown and essentially means that even if they were achieving the same yields they would need 50% more land to do so as 1/3 of the land was growing legumes (which pull nitrogen out of the air) which would be ploughed under to enrich the soil with nitrogen.
There are two excellent books outlining how the projected peak human population of about 10 billion late in the 21st century can be fed. The first is Vaclav Smil's (I would recommend all of his books they are eye opening scholarly works on energy and food) Feeding the World: A Challenge for the 21st Century
and the second is Gordon Conway's The Doubly Green Revolution: Food For All in The Twenty-First Century.
Both of those books are reviewed here
(along with two other books I haven't read). There are no books on how organic farming could do the same, for the simple reason that it couldn't, at best, support more than about 55-70% of the current world population.