Symbiotic relationships and effectiveness of soybean rhizobia in soils of the Nigerian Savanna

Abstract

Greenhouse experiment was carried out at National Cereal Research Institute Badeggi, Nigeria in 2013. The treatments were N sources (0 kg N ha-1, 100 kg N ha-1, USDA110 traded as Biofix, 532c traded as Legumefix) and 30 sites across the Nigeria Savanna fitted to Completely Randomized Design with three replications. Results revealed that population density of the indigenous rhizobia was highest in the southern Guinea and lowest in the northern Guinea. Similarly, symbiotic effectiveness of indigenous rhizobia was highest in the southern Guinea and lowest in the northern Guinea. Consequently, 50 percent and 20 percent of the locations responded to inoculation with Biofix and Legumefix respectively in the southern Guinea, while the percentage of locations that responded to these inoculants were 60 percent respectively in the northern Guinea , 50 percent and 30 percent in the sudan savanna. It is therefore recommended that the use of these elite inoculants (Biofix and Legumefix) be restricted to Northern guinea savanna while the potentials of indigenous rhizobia native to southern Guinea and sudan savanna be explored in local production of rhizobium inoculants. Keywords: Effectiveness, Inoculation, Population, Rhizobia, Soybean, Symbiotic