International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

Soil properties and hydrological regimes of flooded and non-flooded terrains create different conditions for soil microbial activity. The aim of this study was to characterize the microbiological properties of two profiles of Alluvial-meadow soil, situated on flooded and non-flooded terrace of the Maritsa River and to relate them to some soil physical properties. The main groups of soil microorganisms and the enzyme activity (β-glucosidase and phosphatase) of the soil were determined. It was found that soil characteristics and vegetation cover cause differences in microbiological properties. The soil profile from the first flooded river terrace of the Maritsa River was characterized by the largest amount of cellulolytic microorganisms. The heterotrophic microorganisms, mineral nitrogen – utilizing bacteria, microscopic fungi and actinomycetes prevailed in the soil profile on non-flooded terrace. Higher enzyme activity was also observed in this profile.

Hydrophobicity (water repellency) have negative impact on soil structure, plant growth and production. The knowledge on soil hydrophobic properties is important for proper amelioration of water repellent soils. A monitoring study on hydrophobicity level, microbiological indicators and the realtionships between them in a coal ash reclaimed Technosol under different vegetation cover (pine trees, acacia trees and stubble) was performed. It was found that the surface layers possessed extreme or severe hydrophobicity and below 30 cm depth the soil was slightly hydrophobic. The structure of microbial population changed depending on vegetation. Oligotrophic microorganisms dominated in soils under trees and fungi prevailed in the soil under stubble. The soil under pine trees had the highest microbial parameters. Soil hydrophobicity level was very highly positively correlated with the amount of fungi in both areas under tree vegetation. Under stubble, negative correlation of WDPT with fungi and cellulolytic microorganisms was found. Relations with basal respiration and microbial biomass carbon were weak.