Monoammonium Phosphate Effects on Glyphosate in Soils: Mobilization,Phytotoxicity, and Alteration of the Microbial Community

Eurasian Soil Science - Application of monoammonium phosphate has been demonstrated to re-immobilize glyphosate sorbed by soil under model laboratory experiment conditions. This effect was most...     

Assessment of the Impact of No-Till and Conventional Tillage Technologies on the Microbiome of Southern Agrochernozems

Eurasian Soil Science - Quantitative characteristics of microbial communities in southern agrochernozems of the Stavropol region managed with the use of no-till technology and moldboard plowing...     

Effect of Biochar Amendment and Ageing on Adsorption and Degradation of Two Herbicides

Biochar amendment can alter soil properties, for instance, the ability to adsorb and degrade different chemicals. However, ageing of the biochar, due to processes occurring in the soil over time, can influence such biochar-mediated effects. This study examined how biochar affected adsorption and degradation of two herbicides, glyphosate (N-(phosphonomethyl)-glycine) and diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea) in soil and how these effects were modulated by ageing of the biochar. One sandy and one clayey soil that had been freshly amended with a wood-based biochar (0, 1, 10, 20 and 30% w/w) were studied. An ageing experiment, in which the soil-biochar mixtures were aged for 3.5 months in the laboratory, was also performed. Adsorption and degradation were studied in these soil and soil-biochar mixtures, and compared to results from a soil historically enriched with charcoal. Biochar amendment increased the pH in both soils and increased the water-holding capacity of the sandy soil. Adsorption of diuron was enhanced by biochar amendment in both soils, while glyphosate adsorption was decreased in the sandy soil. Ageing of soil-biochar mixtures decreased adsorption of both herbicides in comparison with freshly biochar-amended soil. Herbicide degradation rates were not consistently affected by biochar amendment or ageing in any of the soils. However, glyphosate half-lives correlated with the Freundlich Kf values in the clayey soil, indicating that degradation was limited by availability there.     

Microbial Communities of Interglacial and Interstadial Paleosols of the Late Pleistocene

Eurasian Soil Science - The taxonomic structure of microbial communities in the Late Pleistocene paleosols of different ages in the Central Russian Upland formed under contrasting climatic...     

The Dynamics of Soil Microbial Communities on Different Timescales: A Review

Eurasian Soil Science - Soil microbial communities are subjected to significant changes over time. The most rapid changes caused by temperature and soil moisture alternations or the by the inflow...     

Seasonal Dynamics of Microbial Biomass in Soddy-Podzolic Soil

Eurasian Soil Science - The seasonal dynamics of the structure of microbial biomass in a soddy-podzolic soil under fallow was assessed using luminescent microscopy. Samples from three soil horizons...     

Microbiomes of the Soils of Solonetzic Complex with Contrasting Salinization on the Volga–Ural Interfluve

The analysis of ribosomal genes has been applied to study microbiomes of two soils of the solonetzic soil complex in the northern Caspian region. These soils—solonetz and quasigleyic chestnut soil—drastically differ in their salinity characteristics. The specificity of the vertical distribution of prokaryotes by the genetic soil horizons from the surface to the depth of 120 cm in these soils is discussed. The differences in the structure of microbiomes in the upper soil horizons can be related to the differences in the vegetation cover of the two soils, whereas the differentiation of microbiomes along the soil profiles is affected by the soil salinization. The solonetz is characterized by a much sharper decrease in the abundance and diversity of microorganisms down the soil profile in comparison with the leached quasigleyic chestnut soil. The total number of prokaryotes is mainly limited by the organic carbon content. In the upper soil horizons, Archaea from the phylum Thaumarchaeota are relatively abundant; their percentage decreases down the soil profiles. In the lower horizons of the solonetz, the genes of Marinobacter bacteria, which are considered marine inhabitants, have been found. It is probable that they persist in the soil since the previous transgression of the Caspian Sea.     

Microbiological parameters of aggregates in typical chernozems of long-term field experiments

The changes in microbiological parameters of aggregates (1–2 mm) in typical chernozems under different land uses as dependent on the intensity and character of anthropogenic loads were studied with the help of the real-time polymerase chain reaction (PCR). The samples from the following long-term field experiments were examined: permanent black fallow, continuous cultivation of potato, 17-year-old unmanaged fallow after permanent black fallow, and annually mown reserved steppe. The soil samples were treated in two ways. In the first case, the samples were air-dried, sieved through the screens to separate aggregate fraction of 1–2 mm, and microbiological parameters were determined in this fraction. In the second case, the samples were frozen immediately after the sampling, and the aggregates of 1–2 mm were manually separated from the samples before the PCR analysis. It was shown that air-dry aggregates of chernozems could be used for the quantitative analysis of DNA of microbial community in comparative studies. According to the quantitative estimate of the content of DNA fragments from different phylogenetic groups, the bacterial community was most sensitive to the type of the soil use, and its restoration after the removal of extreme anthropogenic loads proceeded faster than that of other microorganisms. The content of archaeal DNA in the chernozem under the 17-year-old unmanaged fallow did not differ significantly from its content in the annually plowed chernozems. The changes in the content of micromycetal DNA related to anthropogenic load decrease were intermediate between changes in the contents of archaeal and bacterial DNA.