@ARTICLE {LAL: 1983a, title = {Effects of soil moisture, bulk density and tillage methods on tropical root crops}, author = {Lal, R. and Ghuman, B. S. and Maduakor, H. O. }, journal = {Paper presented at the Sixth Symposium of the International Society for Tropical Root Crops}, year = {1983}, pages = {21--26}, note = {RTB; Root and Tuber}, }