@ARTICLE {TIAN:1999a, title = {An improved cover crop-fallow system for sustainable management of low activity clay soils of the tropics}, author = {Tian, G. and Kolawole, G. and Salako, F. K. and Kang, B. }, journal = {Soil Science}, year = {1999}, volume = {164}, number = {9}, pages = {671--682}, issn = {0038-075X}, }