Kellogg LTER

Soil Sci. Soc. Am. J. 73:2078-2086 (2009) reports that a conventional tillage farming trial, at the Kellogg Long Term Ecological Research site, using a corn, soy, and wheat rotation with additions of nitrogen fertilizer resulted in a 12% loss of soil carbon, from approximately .93% C to .82% C between 1988 and 2006, to a 15 cm depth. Other trials with either no nitrogen fertilizer, or using a cover crop, showed declines of 7% and 2%, respectively in soil carbon over the same period.