Field experiments were carried out in the Savelugu/Nanton and Yendi Municipalities in the northern region of Ghana in 2014 to investigate the effect of inoculation, rates and time of nitrogen fertilizer application on growth, yield, agronomic efficiency of mineral N and biological nitrogen fixation of soybean. The experiment was laid out in a split-split plot, arranged in a randomized complete block design with four replications at both locations.