Author Statement :
sponsored by Divisions S-1, S-2, and A-5 of the American Society of Agronomy and the Soil Science Society of America in Atlanta, Georgia, 29 Nov.-3 Dec. 1981 ; editorial committee, D.W. Nelson, chmn., D.E. Elrick, K.K. Tanji ; managing editor, David M. Kral ; assistant editor, Sherri L. Hawkins.
