Influence of microbial fertilizers on microbiological and enzymatic decomposition of carbohydrates in agrogenic soil

Boyka Malcheva

Abstract: Experiment analyzed the influence of microbial fertilizers of different composition on the microflora and the activity of carbohydrate-degrading enzymes in agrogenic soil. Biogenicity of the analyzed variants increases after fertilization compared to the unfertilized sample. The total amount of microorganisms is higher when using combined microbial fertilizers containing different groups of microorganisms compared to the fertilizer, which contains one bacterial species. However, the mineralization activity is lower in the variants with the combined fertilizers. The main share in the composition of the total microflora is occupied by non-spore-forming bacteria and bacilli, and the least represented are actinomycetes and micromycetes. Combined microbial fertilizers increase the activity of amylase, cellulase and invertase to a higher degree than microbial fertilizers containing one type of bacillus. The opposite tendency is found for catalase activity. The activities of the enzymes increase during the action of the fertilizers. The correlation between the total microflora and the enzymes is very strong (amylase, cellulase, invertase) and strong (catalase) in all variants. The studied microbiological and biochemical indicators can be used as sensitive biomarkers to determine the influence of microbial fertilizers on the decomposition of carbohydrates in different types of soils.

Keywords: carbohydrates; enzymes; microbial fertilizers; soil microflora

Date published: 2021-06-24