Research on the use of Rhizobia inoculants has been conducted in Africa since 1950s. However, the technology has not been widely applied by farmers on the continent. In Kenya, wide-scale adoption of this innovation among the smallholder farmers is still low. The aim of this study was to examine factors that drive the use of BIOFIX®Rhizobia inoculant, a product of Kenya, and its profitability in smallholder farms. Data were collected from 210 soybean (Glycine max) farmers in western Kenya. Logit and tobit regression models were used to assess drivers of the inoculants use and gross margin analysis to examine profitability. The area under the crop, distance to local markets, knowledge of legume root nodules, education level, contacts with organisations promoting biological N fixation (BNF) technologies, group membership, soybean market and location of the farm based on agro-ecological zone were factors that determine the use of the inoculants. There was a significant difference in yields between farmers who inoculate soybean (864 kg ha-1) and those who do not (686 kg ha-1) (P<0.01). The difference in gross margin achieved by inoculant users (US$ 278 ha-1) and non-users was highly significant (P<0.01).
African Crop Science Journal, 22 (3), 205 - 213