Soybean in symbiosis with Bradyrhizobium japonicum is able to satisfy its nitrogen (N2) demand with biological nitrogen fixation (BNF). However, BNF can be affected by molybdenium deficiency because this micronutrient is part of the nitrogenase enzyme responsible for the process. An experiment was conducted under field conditions on a Red Latosol (Oxisol) in Palotina, state of Paraná, Brazil. The effects of seed treatments with Mo, B. japonicum inoculation as well as foliar Mo fertilization on soybean yield were evaluated. Four Mo rates (0, 40, 80 and 160 g ha-1) were applied as foliar fertilizer in two Mo application forms (without Mo, seed treatment with Mo 40 g ha-1) combined with and without B. japonicum inoculation. There were no significant effects of the seed treatments with Mo, inoculation with B. japonicum and foliar Mo fertilization on soybean yield were observed. The economic analysis showed negative effects; only when 80 g ha-1 were applied as foliar fertilization and the seed treatment with 40 g ha-1 an economic yield was obtained.
foliar fertilization; seed treatments; micronutrient; rhizobion
