soil depletion...environmental degradation....higher food prices??
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http://culturechange.org/cms/index.p...d=107&Itemid=1
"Ethanol is an agribusiness get-rich-quick scheme that will bankrupt our topsoil.
Nineteenth century western farmers converted their corn into whiskey to make a profit (Rorabaugh 1979).
Archer Daniels Midland, a large grain processor, came up with the same scheme in the 20th century. But ethanol was a product in search of a market, so ADM spent three decades relentlessly lobbying for ethanol to be used in gasoline. Today ADM makes record profits from ethanol sales and government subsidies (Barrionuevo 2006)."
"Long before there was "Peak Oil", there was "Peak Soil". Iowa has some of the best topsoil in the world. In the past century, half of it?s been lost, from an average of 18 to 10 inches deep (Pate 2004, Klee 1991).
Productivity drops off sharply when topsoil reaches 6 inches or less, the average crop root zone depth (Sundquist 2005).
Crop productivity continually declines as topsoil is lost and residues are removed."
"When you take out more nutrients and organic matter from the soil than you put back in, you are "mining" the topsoil. The organic matter is especially important, since that?s what prevents erosion, improves soil structure, health, water retention, and gives the next crop its nutrition. Modern agriculture only addresses the nutritional component by adding fossil-fuel based fertilizers, and because the soil is unhealthy from a lack of organic matter, copes with insects and disease with oil-based pesticides.
"Fertilizer energy" is 28% of the energy used in agriculture (Heller, 2000). Fertilizer uses natural gas both as a feedstock and the source of energy to create the high temperatures and pressures necessary to coax inert nitrogen out of the air (nitrogen is often the limiting factor in crop production). This is known as the Haber-Bosch process, and it?s a big part of the green revolution that made it possible for the world?s population to grow from half a billion to 6.5 billion today (Smil 2000, Fisher 2001)."