@INPROCEEDINGS {TIAN:1999b, title = {Improved cover crop fallow}, author = {Tian, G. }, booktitle = {Soil fertility initiative for sub-Saharan Africa: proceedings of the SFI/FAO consultation, World Soil Resources Reports, Rome, Italy, 19–20 November 1998}, year = {1999}, pages = {51--52}, publisher = {FAO}, address = {Rome, Italy}, }