The field and screen
house experiments were carried out in the 2013 cropping season to assess the
effects of B. japonicum inoculation
and phosphorus supplementation on the uptake of micronutrients in the cowpea.
The experiment was laid out in a split plot design where the main plots
comprised two inoculation treatments (with and without B. japonicum inoculation) and sub plots included four different
levels of phosphorus (0, 20, 40, and 80 kg P/ha). The results showed a
significant improvement in the uptake of micronutrients in the B. japonicum inoculated treatments over
the control. Phosphorus supplementation (40 kg P/ha) also showed a significant
increase in the uptake of some micronutrients while decreasing the uptake of Zn
in some plant organs. There was also a significant interaction between B. japonicum inoculation and phosphorus
in the root uptake of Zn for the field experiment.