Fig. 6. Cumulative changes in soil C from 1991 to 2000 caused by changes in tillage intensity and crop rotation for the Mid-Continent Intensive (MCI) region. The magnified area is an enhanced view of Wayne County, Iowa. Wayne County includes a diverse set of cropping practices, tillage intensities, and soil types, and illustrates a range of soil C gain and loss at a 900-m2 resolution within a 10-yr period.