POTENTIAL of ENZYMATIC METHODS and BIOLOG ECOPLATE ANALYSIS for INVESTIGATION of MICROBIAL FUNCTIONALITY in AGRICULTURAL SOILS

Abstract

Agricultural systems and applications affects the soil ecological conditions and microbial structure.However, it is important that the interventions do not disturb the balance and quality of the microbialcontent of the soil. For this reason, enzymatic methods and Biolog Ecoplate method were applied toresearch and evaluate the status of functional microbial diversity in four different agricultural soilsamples (A, B, C, D).The results indicated that the pH, electrical conductivity, amounts of total nitrogen (N) and humiditywere generally similar but calcium carbonate rates were higher in A and B agricultural soils. Soilenzymatic activity results showed some differences among the four different agricultural soils. Theactivity measurements of urease, phosphatase and dehydrogenase were high and results showed thedifferanties. Enzymatic activities and microbial populations correlated with each others and content oforganic carbon.Evaluation of substrate utilization profiles and the diversity indices concluded that microbialcommunity structure and composition were different related to various conditions. The average wellcolor development (AWCD) which was calculated in the Biolog EcoPlate analysis showed somevariations in the catabolic ability of four different agricultural soil samples’ microbial communities.Compared to other samples, C and D agricultural soil samples had a higher overall AWCD value.AWCD of C soil was significantly higher than in the others. Lowest used substrates were ?-Cyclodextrin, ?-Ketobutyric acid, ?-Methyl-D-glucoside, ?-D-Lactose and 2- hydroxybutyric acid.The most extensively used substrates were aminoacids and carbohydrate groups. These resultsindicates the degradation potential. With the Biolog EcoPlate and enzymatic measurements, changesin the microbial community in agricultural soils can be detected, and also agricultural managementand application methods for tillage can be evaluated.