@INBOOK {LAL:1979l, title = {Effects of cultural and harvesting practices on soil physical characteristics}, author = {Lal, R. }, year = {1979}, type = {Soils Research in Agro-Forestry edited by H.O. Mongi and P.A.Huxley}, pages = {327--352}, publisher = {ICRAF}, address = {Nairobi}, }