**ABSTRACT**

Owing to the rising costs of chemical fertilizers and the growing environmental concerns, there is an ever increasing interest in the role of soil microorganisms in crop nutrition and soil fertility restoration. A field study was therefore conducted at Pawe Agricultural Research Center during 2010 main cropping season to determine the influence of *Bradyrhizobium japonicum* inoculation and N and P fertilizers application on nodulation, yield and yield attributes of soybean. Three levels of N (0, 11.5 and 23 kg N ha^{-1}); three levels of P (0, 23 and 46 kg P_{2}O_{5} ha^{-1}) with two levels of Rhizobium were arranged in RCBD in factorial combinations with three replications. Nodule number, nodule fresh and dry weights, plant height, number of pods and seeds per plant, 100 seeds weight and grain yield responded significantly to the interaction effects of *B. japonicum* inoculation and application of N and P fertilizers but nodule volume, seed and biomass yields, and harvest index were significantly affected by the main effects of any one or more of the factors and interaction of any two of the factors. The maximum numbers of nodules of 80.26, fresh and dry weights of 3.77 and 0.99 gm./plant respectively; were measured by combined effect of 11.5 kg N/ha, 46 kg P_{2}O_{5}/ha and *B. japonicum*. Similarly the highest nodule volume of 3.53 and 3.27 ml/plant were measured after applications of 46 kg P_{2}O_{5}/ha with *B. japonicum* and with 11.5 kg N/ha respectively. The highest plant heights of 79.26 cm followed by 76.94 cm were measured by application of 46 kg P_{2}O_{5}/ha with *B. japonicum* and 46 kg P_{2}O_{5}/ha itself respectively. Seed yield significantly increased to 11.91 gm /plant and 15.97 gm /plant following application of *B. japonicum* alone and 46 kg P_{2}O_{5}/ha with *B. japonicum* respectively. Applied 23 kg/ha brought the highest plant biomass of 27.25 gm/plant. Inoculation with 46 kg P_{2}O_{5}/ha and the combined effects of 11.5 kg N/ha, 46 kg P_{2}O_{5}/ha and *B. japonicum* resulted 73.93 and 80.66 number of pods per plant respectively. The maximum 100.60 numbers of seeds per plant were counted during inoculation of *B. japonicum* with 46 kg P_{2}O_{5}/ha. The maximum 100-seed weight of 16.96 gm and grain yield of 3151.88 kg/ha were produced by combined application of 11.5 kg N/ha, 46 kg P_{2}O_{5}/ha and *B. japonicum*. Each nodule attributes were significantly and positively correlated each other and with each yield and yield attributes. The results showed that growth and yield potential of soybean and an increase N_{2} fixing can be achieved by using *B. japonicum* and P fertilizer with reduced level of N as starter fertilizer.

**References**

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