An experiment was conducted at Campinas, State of São Paulo, to study the effect of lime, green manure and mineral fertilizers on the yield of dry beans (Phaseolus vulgaris L.) on a poor soil with «cerrado» vegetation. The response to green manure was positive, but small, in the presence of NPK, and negative in the absence of that fertilizer. Lime and phosphorus were the principal yield increasing factors. In the average of two years, the effect of phosphorus corresponded to +123%. In the first year, superphosphate was superior to Olinda (rock) phosphate; in the second, however, it was inferior. Liming enhanced the effect of superphosphate but depressed that of Olinda phosphate. While the average annual yield of the «no lime, no fertilizers plots was only 174 kg/ha (kilograms per hectare), that of the plots treated with lime, green manure, phosphorus (in the green manure year), and additionally with NPK in the first and exclusively with N in the second dry bean years reached 910 kg/ha. This yield is equivalent to those normally obtained in fertile soils.