Converting crop residues into cellulosic ethanol sounds to many people like a good idea — certainly better than using food crops themselves. Yet according to respected USDA soil scientist Ann Kennedy, the stems and leaves left over after crops are harvested may have more value if they are left on the ground, especially in areas receiving less than 25 inches of precipitation annually.
That includes most of the United States (click on link to see map) west of the 100th meridian, which runs roughly from Bismark, S.D. through Laredo, Texas.
To regular readers of Gristmill, this probably does not sound like news, but to others it may.
According to Kennedy (the full story can be found at ScienceDaily), a USDA Agricultural Research Service soil scientist and adjunct professor of crop and soil sciences at Washington State University:
“With cultivation, organic matter tends to decline in most places around the world. In the more than 100 years that we have been cultivating soils in the Palouse [the wheat-growing region of Eastern Washington, Northern Idaho and Northeast Oregon] we have lost about half of the original organic matter.
In term... Read more