@PROCEEDINGS {KANG:1984d, title = {Management of low activity clay Alfisols and Ultisols}, author = {Kang, B. and Spain, J. M. and Uehara, G. }, booktitle = {Presented at the Annual Meeting of the American Society of Agronomy, 25-30 November}, year = {1984}, publisher = {Las Vegas}, address = {Nevada, U.S.A.}, }