Response of groundnut (Arachis hypogea) to rhizobia inoculation, mineral nitrogen and inoculation amendment at the two agro ecological zones of northern Nigerian savannah

Nitrogen is the most limiting major nutrient required by all living plants. Nitrogen fertilizer is costly and too much application of nitrogen causes detrimental effects to our ecosystem. Alternatively, the use of commercial microbial inoculants will be an alternative to chemical fertilizer for the small holder farmers in northern Nigeria. Groundnut (pea nut) was selected as a test crop for the inoculation. The experiment was conducted at Sudan savannah in Kano State and Guinea savannah in Bauchi state of Nigeria during the 2016 cropping season. The design of the experiment was RCBD with seven treatments and four replications in each site. Two rhizobia inoculants were tested on groundnut in two agroecological zones of northern Nigeria to monitor their performance and their ability to establish symbiotic and nodulate the crops. The treatments combinations were; histic, biofix, nitrogen, cattle manure, histic + cattle manure, biofix + cattle manure and control. In the groundnut field, Biofix produced higher nitrogen fixed than all treatments in the Sudan savanna, while in the Guinea savanna no significant differences (P = 0.67) were observed between the treatments and the control. However, inoculated plots had higher nitrogen fixation than the control.