Field testing of the effectiveness of bacterial fertilizer in Nepal

In Nepal, where fertilizer is badly needed to replenish the severely eroded soil, nitrogen-fixing bacterial inocula were tested in field trial studies in various localities. Inocula of Azospirillum brasilense and Azotobacter chroococcum were prepared in carrier mixtures of soil and cattle manure. Field trials using these bacterial fertilizers were performed on rice, wheat, and maize over a period of 3 years.Azospirillum inoculum on rice seedlings increased yield by an average of 29.4%, from about 2.1–2.8 Mt ha⁻¹, statistically significant at the 1% level. The effects of Azospirillum on wheat and Azotobacter on maize were not statistically significant at the 5% level, nor were the effects of other compared treatments, namely, urea, compost and green manure. Since the coefficients of variation were high and the sample sizes were small, more trials and replications should be done to establish reliable conclusions.