Micronutrients in agriculture; proceedings of a symposium held at Muscle Shoals, Alabama, April 20-22, 1971, and cosponsored by the Tennessee Valley Authority and the Soil Science Society of America. Editorial committee: J. J. Mortvedt, chairman, P. M. Giordano [and] W. L. Lindsay. Managing editor: Richard C. Dinauer. Assistant editors: Vonda S. Clark [and] Patricia Eith.