The Carrington silt loam occurs extensively on the gently rolling uplands throughout northeastern central Iowa and in the eastern central counties. It is one of the more important soil types in the Iowan drift soil area. The map (fig. 1) shows its approximate occurrence.

Crop yields are generally quite satisfactory on this soil, but some areas are not producing properly, and in many cases much larger yields per acre may be secured by the adoption of better methods of soil management. Suggestions have been offered in a previous publication* which if adopted will make this soil more productive and insure its permanent fertility. These suggestions have been incorporated in what is known as the Iowa system of soil management.