Microbial features of newly-formed soils of disposal fields from sugar refineries
Newly-formed soils of wastewater disposal fields from two sugar refineries in forest-steppe zone (Kursk region, European Russia) were studied. Among factors of soil formation on sugar wastewater lagoons the geochemical influence of wastewater mixed with diluted filtration and transport-washing sludge stands out. We have revealed key physico-chemical and microbiological properties of such soils formed under different moisture regimes, substrates, vegetation, and duration of use. Compared to conditionally background soils (Luvic (Anthric) Chernozems), the newly formed soils show shift of pH values to alkaline ones, carbonation, increase of soil organic carbon, growth in mobile forms of phosphorus, potassium and nitrogen. Microflora in studied soils is identical in composition to background soils, but it differs significantly in structure. In soils formed in the decommissioned wastewater lagoons of an active sugar refinery, a higher number of bacteria with low participation of Micromycetes and Actinomycetes was noted, which indicates active destruction of organic matter. In soils of the recultivated and completely abandoned sugar wastewater lagoons indicated as Calcaric Someric Phaeozem, a higher number of Actinomycetes was noted than in the background soils.