Evolution of An Alfisol Into a Mollisol with 150 Years of Cropping in Iowa.

We examined three fields that were contiguous with one another and an older growth forest in Johnson County, Iowa. The fields had been cultivated for 150, 100, and 50 years, respectively. All pedons sampled were from Fayette (fine-silty, mixed superactive, mesic Typic Hapludalf) map units. The modern soils differed significantly. This paper describes their morphology and explains how their anthropedogenic pathways are diverging.