Effect of Carrier-based Rhizobium leguminosarum Inoculants on the Soil Physicochemical Characteristics, Nodulation and Growth of Soybean

Aims: To evaluate the effect of carrier-based inoculants on the soil physicochemical characteristics, nodulation and growth of soybean.

Study Design: Examination of different carrier.

Place and Duration of Study: Department of Applied microbiology and Brewing, Nnamdi Azikiwe University, Awka, from February 2014 and March, 2015.

Methodology: Field experiment of soybean mixed with sawdust and cassava peels inoculated with Rhizobium leguminosarum. Growth parameters of soybean and physicochemical characteristics of the soil were checked after 40 days of planting.

Results: There was significant increase in the calcium, magnesium and potassium contents, total nitrogen and conductivity of the soil after the field experiment. The shoot height was significantly different from the control at p ≤ 0.05, though the growth parameters were not statistically significant from the control. Nonetheless, there was marked increase over the control in nodulation and other growth parameters with the highest found in soybean plant inoculated with cassava-based Rhizobium leguminosarum.

Conclusion: This study thus showed since the carrier-based Rhizobium leguminosarum inoculants increased the physicochemical characteristics of the soil, nodulation and soybean growth; therefore such inoculant is an effective alternative to chemical fertilizers in enhancing the plant growth.