Microorganisms play vital role in keeping soil healthy. Bacteria, Fungi and Actinobacteria are active in degrading soil organic matter which improves soil ecosystem functioning. There exists a dearth of information on the influence of land-use on diversity of microbes in different soil aggregate sizes in Northern Guinea Savanna of Nigeria. This study assessed the diversity of soil microbes under six different land-use practices namely forest, fallow, pasture legume, pasture cereal, date palm plantation and continuous cultivated. In each land-use soil samples were collected at two depths (0-5 cm and 5-20 cm). The soil samples were divided into two parts, one part was left as collected from the field sites (bulk soil) and the other part was separated into three aggregate fractions (>250 µm, >53 µm and <53 µm). Bacteria, Fungi and Actinobacteria were cultured, isolated and identified, and some soil chemical properties were determined. Colony forming units per gram of soil (CFU/g soil) was computed for the soil microbes. Results revealed that Bacteria is the predominant soil microbe followed by Actinobacteria and then Fungi in all the land-uses. Bacteria population ranged from 1.49x107to 8.65x107CFU/g soil, Actinobacteria population ranged from 9.32x105 to 5.85x106 CFU/g soil and Fungi population ranged between 6.75x104 and 4.21x105 CFU/g soil. Higher microbial population were observed in forest soil than soils of the other land-uses. Continuously cultivated land had the least microbial population. Silt + clay soil fraction had significantly higher bacteria while the bulk soil was significantly richer in fungal population.
DIVERSITY OF MICROBES IN SOIL AGGREGATE FRACTIONS UNDER DIFFERENT LAND-USE IN NORTHERN GUINEA SAVANNA, NIGERIA
