Biological N fixation activity in soybean can be estimated based on nodule dry weight and is increased by additional inoculation

The response of soybean to biological nitrogen fixation (BNF) varies due factors such as plant variety, soil, and environmental conditions, which can compromise the N2 capacity. objective this study was evaluate additional inoculation with B. japonicum at different growth stages a strategy improve fixation. This determined by studying nodulation BNF isotope dilution method. experiment carried out under greenhouse conditions in soil without cropping history. Inoculated increased nodulation, biomass, yield components compared un-inoculated soybean. Additional V3 stage showed promising results maintaining later stages. A strong correlation observed between nodule dry weight fixation, providing an easily available method estimate differences activity treatments. Moreover, efficient is crucial sustain high yields BNF, shown pod weight.