Soil erosion in the cornfield on William Keefe's farm in Benton County, Indiana. Note subsoil, and gradation to fertile topsoil from left to right. This county has the best soil in the state. This field has been in hay or pasture six out of the last sixteen years; the slope at this point in the field is three to five percent. The owner, who did not know how to stop this erosion, had followed the plan of filling in gullies by plowing until two years ago; thus this picture shows gullying on the field in two years' time. Rotating crops: corn, wheat, clover, would have stopped this erosion