Frontiers in Environmental Microbiology | 2021
Micro and Macro (Organisms) and Their Contributions to Soil Fertility
Abstract
Soil chemical properties and microbial populations were always determined in soil in order to compare the contributions of microorganisms to soil fertility and to sustain agricultural plant growth. The ability to supply essential plant nutrients (phosphorus (P), potassium (K), nitrogen (N), sulphur (S) etc.) and soil water in adequate amounts and proportions for plant growth and reproduction; and the absence of toxic substances which may inhibit plant growth. This research work therefore aimed at understanding the different types of microbes present in soil and their various contributions to soil fertility. Sample collection normally ranges from 0-20 cm depth in the soil. These samples were air dried, passed through a 2-mm sieve before soil properties were determined following standard methods. Fresh soil samples were used to determine the number of soil microorganisms via the dilution spread plate technique using the nutrient agar for bacteria and potato dextrose agar for fungi. Research showed that the forest and fallow lands had significantly lower pH value, available P, exchangeable K and Na, but significantly higher exchangeable H and bacteria population than the cultivated land. The mean exchangeable Ca was significantly higher in the cultivated land than in the fallow land but similar to that from the forestland. The fungi population was also higher in the forestland than in others which are similar statistically. The mean soil organic matter, total N, exchangeable Mg, exchangeable Al and CEC were similar in all the land use types. Contributions of microorganisms to soil fertility were generally more in the uncultivated lands, an indication that tillage operations may have affected the microbial populations. Also the relationship between some soil chemical properties and microbial densities signify important roles microorganism play in soil nutrient build up.