Determination of the effect of farm-made bio inoculant on occurrence of soil-borne microbes and performance of soybeans under screen-house conditions in Soroti district

Abstract

Bio inoculants play an important role in agriculture as plant growth promoters and improvers of soil fertility. However, little information is known about dynamics of new farm-made bio inoculants and how they affect soil microbes and soil nutrient response of plants. Here, in a screen house experiment involving a complete randomized design with three replications and three treatments that is Rhizobia bio-fertilizer, farm made bio inoculant and the control, we analyzed the effect of use of a farm-made bio inoculant on the soil microbial colony counts, growth and yield performance of Soybean. We found out that Treatments with Rhizobia bio fertilizer and the farm- made bio inoculant recorded a significant increase (P<0.01) in the soil microbial colony counts, growth and yield performance of Soybean from the different parameters studied, which might partly be attributed to inoculation that led to increased microbial populations whose ability to produce IAA, assimilate and acquire essential nutrients enhanced plant growth and yield. Notably, soils amended with the Rhizobia bio-fertilizer had the highest significant increase in the bacteria colony counts (32,656,667cfu/ml) followed by the farm-made bio inoculant (30,769,167cfu/ml) and the control (16,082,500cfu/ml).This was the same for the yield performance of Soybeans, where plants treated with the rhizobia bio-fertilizer had the highest grain yield (1635kg/ha),followed by those treated with the far-made bio inoculant (140kg/ha) and then the control (942kg/ha), a trend which was reflected in all the seasons. These findings provide a crucial role of soil microbial populations in the soil fertility and plant performance. Hence, recommendation emphasized the need to do soil testing to ascertain the different soil factors would affect the relative abundance of the soil microbes even before the bio inoculant is applied. A recommendation was also made to increase on the number and specific times of applying the farm made bio inoculant and also formulate the farm-made bio inoculant while ensuring microbes with a better symbiotic relationship with the plant are present in it.