To study the effects of increasing levels of nitrogen on soybean yield with and without inoculation, two field experiments were carried out on two sandy soils of the State of São Paulo, namely a Red Dark Latosol, sandy phase, in the Municipality of Regente Feijo and a Podzolizado Lins-Marília Soil, variation Marília, in the Municipality of Herculãndia. The experiment in Herculãndia showed an effect of innoculation on yield, whereas the experiment in Regente Feijo showed a linear and cubic effect of rates of nitrogen on yield. Chlorosis appeared in both experiments where nitrogen has not been applied, but it was not permanent in Regente Feijo experiment, as hapened in Herculandia experiment.