maps developed by Linda Zellmer, Government Information & Data Services Librarian, Western Illinois University Libraries, with data from the U.S. Census Bureau and the Census of Agriculture
sponsored by divisions S-4 and C-6 of the Soil Science Society of America, Crop Science Society of America, and the American Society of Agronomy in Anaheim, Calif., 28 Nov.- Dec. 1982 ; editorial committee, R.M. Welch, W.H. Gabelman