Microbial activity and community level physiological profiles (CLPP) of soil under the cultivation of spring rape with the Roundup 360 SL herbicide.

PURPOSE: The use of glyphosate in agriculture raises a lot of controversy because research concerning its impact on the soil provides contradictory information. However, despite these negative opinions, glyphosate is still used in agricultural practice. Therefore, for a more complete assessment, the authors carried out research using traditional microbiological methods and a modern method of metabolic profile analysis in glyphosate-treated soil. METHODS: The study was carried out on the soil witch was sown with six cultivars of rapeseed. Seven days before harvest, the plants were sprayed with the herbicide. The analyses consisted in determining the number of selected groups of microorganisms, biochemical and enzymatic activity, and differentiation of the catabolic potential of soil microbial communities. RESULTS: The results showed significant changes in the analyzed parameters. Respiratory activity and ammonification processes were stimulated in the treatments with rapeseed cultivation treated with the herbicide. Changes in the enzymatic activity were generally positive. The EcoPlate assessment of microbial community catabolism showed that the highest activity was recorded in the soil sown with the cultivars Belinda, Tamarin, and Sw svinto. Concurrently, these soils were characterized by the highest correlations between rapeseed cultivar and metabolic activity. CONCLUSION: Cultivation of specific plant varieties that reduce the negative effect of herbicides used in agriculture may be one of the methods to prevent soil degradation. In our research, Belinda turned out to be a cultivar, under the cultivation of which an increase in the activity of microorganisms was recorded most frequently compared to soil not sown with rapeseed. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40201-021-00753-3.

Effect of reclamation treatments on microbial activity and phytotoxicity of soil degraded by the sulphur mining industry.

The aim of the work was to determine the trend, intensity and changes of selected microbial and phytotoxic parameters of degraded soil in the area of former sulphur mine reclaimed by post-flotation lime (PFL), sewage sludge (SS), mineral wool (MW- mixed with soil, MWP-pad) and mineral fertilizer (NPK). The following parameters: number of proteolytic bacteria and fungi, ammonification, nitrification, activities of alkaline phosphatase and arylsulphatase Lepidium sativum growth index (GI) and phenolic compounds were analysed in the soil in second and third year of the experiment. The addition of the SS separately or in combination with other remediation agents was found to be the most valuable for the number of microorganisms, intensification of nitrification process and enzymatic activities. In objects where other materials were added without sewage sludge, the inhibition of fungal growth as well as alkaline phosphatase and arylsulphatase activities was observed, however the inhibitory effect declined with time. The observed increase of GI shows the long-term, positive effect of treatments on soil properties concerning plant growth. The use of lime and lime together with sewage sludge contributed to the decrease in the content of phenolic compounds in the reclaimed soil.

Soil microbial functional and fungal diversity as influenced by municipal sewage sludge accumulation.

Safe disposal of municipal sewage sludge is a challenging global environmental concern. The aim of this study was to assess the response of soil microbial functional diversity to the accumulation of municipal sewage sludge during landfill storage. Soil samples of a municipal sewage sludge (SS) and from a sewage sludge landfill that was 3 m from a SS landfill (SS3) were analyzed relative to an undisturbed reference soil. Biolog EcoPlatesTM were inoculated with a soil suspension, and the Average Well Color Development (AWCD), Richness (R) and Shannon-Weaver index (H) were calculated to interpret the results. The fungi isolated from the sewage sludge were identified using comparative rDNA sequencing of the LSU D2 region. The MicroSEQ® ID software was used to assess the raw sequence files, perform sequence matching to the MicroSEQ® ID-validated reference database and create Neighbor-Joining trees. Moreover, the genera of fungi isolated from the soil were identified using microscopic methods. Municipal sewage sludge can serve as a habitat for plant pathogens and as a source of pathogen strains for biotechnological applications.

Microbiological hazards resulting from application of dairy sewage sludge: effects on occurrence of pathogenic microorganisms in soil.

The aims of this study were to (1) examine the extent of bacterial contamination of soils subjected to exposure to dairy sewage sludge applied to soils as measured by determination of number of bacteria from the Escherichia coli family and (2) determine the effects of dairy sewage sludge and straw on populations of other microbial species present in gray-brown podzolic soil. The gray-brown podzolic soil was formed from heavy loamy sand, which is characterized by the following granulometric composition: a sand fraction, 65%; a silt fraction, 19%; and a silt and clay fraction; 16%. The brown soil was formed from silt-loam and characterized by the following granulometric composition of silty-clay deposit: sand fraction, 8%; silt fraction, 48%; and clay and silt fraction, 46%. In dairy sewage sludge the total bacteria number as defined by Alef and Nannipieri (1995) was 51 x 10(4) colony-forming units (cfu)/ kg dry matter (dm), fungi total number 10 x 10(3) cfu/ kg dm, and E. coli bacteria 9.5 x 10(3) most probable number (MPN)/kg dm. In dairy sewage sludge mixed with straw, total number of bacteria and total number of fungi decreased to 10(3) and 10(2), respectively. Competition for nitrogen, glucose, and lactose and organic acids such as acetic and succinic with soil microorganisms, as well as soil conditions such as lack of oxygen, lower soil pH, and temperature, may account for the reduction in the number of E. coli bacteria in soils to which dairy sewage sludge was applied. Dairy sewage sludge may provide a beneficial impact on soil environment and adversely affect microorganisms such that dairy sewage sludge may be used as a safe organic fertilizer.

Populations of selected microbial and fungal species growing on the surface of rape seeds following treatment with desiccants or plant growth regulators.

The aim of this study was to determine the effects of desiccants and plant growth regulators on selected microbial species affecting rape seeds, with special emphasis on the growth of fungi and identification of the genus and species composition. The experimental material in the study was seeds of winter rape cv. Californium that were collected from the field during combine harvest. The chemical agents applied, both desiccants and growth regulators, generally decreased the populations of bacteria occurring on the surface of rape seeds. The responses of fungi depended upon the type of agent applied and were manifested as either stimulation or inhibition of the growth of the fungal species. The fungi isolated from the surface of rape seeds were characteristic of those found in the field environment (Cladosporium and Penicillium) and typical for those present on the surface of rape seeds (Alternaria).