The Influence of Soil’s Physicochemical Properties and Land Use Systems on the Abundance of Actinomycetes Populations

Aims: In this study, we assessed the effect of physicochemical properties of soils from different land use systems on the population of Actinomycetes. Study Design: A cross sectional survey design in line transect sampling was used in collection of samples from land use systems. A 4×6×3 factorial experiments laid in completely randomized design was used in determining Actinomycetes population in land use system and media type culture. Place and Duration of Study: The study was conducted in Meru south sub-county, Kenya, between January 2019 and July 2019. Methodology: Cultural growth of Actinomycetes was determined using four different media type culture. The physicochemical properties of soil were evaluated using standard laboratory methods. The data obtained were analyzed using analysis of variance and significantly means were separated using Least Significance Difference at α = 0.05 in SAS version 9.4. Correlation analysis was used to determine the relationship between soil physicochemical properties and Actinomycetes population.  Actinomycetes population varied significantly (p < 0.05) among the different land use systems. Results: The study's findings revealed significant variations (p < 0.05) in Actinomycetes populations across the different land use systems. The type of media used significantly influenced the growth and proliferation of Actinomycetes colonies, with the Starch casein medium exhibiting the highest number of colonies (3.4 × 105 cfu/ml of soil sample) and the modified Luria Bertani (M1) medium showing the lowest (1.7 × 105 cfu/ml). The Actinomycetes populations demonstrated significant variations (p < 0.05) among the different land use systems. Correlation analysis revealed a moderate positive correlation (r = 0.63407; p < 0.0001) between Actinomycetes population and soil pH, as well as weaker positive correlations (r = 0.3375; p = 0.012) between soil moisture content and Actinomycetes population, and available potassium and Actinomycetes load (r = 0.31483; p < 0.0001). Conclusion: The study concludes that the population of Actinomycetes was affected by soil physicochemical properties and consequently land uses.