Distribution of fungi and bacteria in the soils of the University of Ilorin Teaching and Research Farm

Abstract

The occurrence of fungi and bacteria in Afon, Tanke, Badi, Bolorunduro and Ilemona soils of the University of Ilorin Teaching and Research Farm and the impact of some physicochemical properties of the soils on distribution of microorganisms were studied. The soil dilution technique was used to isolate bacteria and fungi on Nutrient Agar and Potato Dextrose Agar Plates respectively. Cultural and microscopic characteristics were employed in the identification of isolates. The population density of fungi in the soils was in the order Afon > Ilemona > Tanke > Bolorunduro > Badi series while that of bacteria was in the order of Afon > Tanke > Bolorunduro > Badi > Ilemona series. The high microbial load of Afon series was attributed to a combination of factors such as its relatively high organic matter content (0.20%) and Effective Cation Exchange Capacity (9.93), the sandy loam texture and the pH (5.7). A variety of fungal and bacterial species associated with nitrogen fixation and organic matter decomposition were isolated from all the soils. The mycoflora of Ilemona soil was dominated by saprophytic Aspergillus spp while plant pathogenic moulds such as Colletotrichum and Fusarium species occurred frequently in the other soils. The frequency of occurrence of Colletotrichum sp in Afon was 52%, while Fusarium spp was 87% in Badi, 36% in Tanke and 5% in Bolorunduro. The occurrence of enteric bacteria in high numbers in Bolorunduro and Ilemona soils was attributed to the presence of grazing cattle in the farmlands. It was concluded that for optimum crop yield, Afon, Badi, Tanke and Bolorunduro soils need to be treated with appropriate fungicides before the cultivation of crops.

JARD Vol. 4 (2) 2005: pp. 218-227