Proceedings of a symposium - Taylor, H. M.,; Box, J. E., Jr.,; Bland, W. L.,; Brown, D. A.,; Coleman, D. C.,; Smucker, A. J. M.,; Snider, R.,; Upchurch, D. R.,; Buxton, D. R.,; Stuber, C. W.,; Mortvedt, John J.,; Ernst, Susan, (American Society of Agronomy, Inc. Crop Science Society of America, Inc. Soil Science Society of America, Inc., 1987)