Effects of tillage technologies and application of biopreparations on micromycetes in the rhizosphere and rhizoplane of spring wheat

The population density and structure of complexes of soil microscopic fungi in the rhizosphere and rhizoplane of spring wheat (Triticum aestivum L.), plant damage by root rot and leaf diseases, and crop yield were determined in a stationary field experiment on a silty loamy soddy-podzolic soil (Albic Retisol (Loamic, Aric)) in dependence on the soil tillage technique: (a) moldboard plowing to 20–22 cm and (b) non-inversive tillage to 14–16 cm. The results were treated with the two-way ANOVA method. It was shown that the number of fungal propagules in the rhizosphere and rhizoplane of plants in the variant with non-inversive tillage was significantly smaller than that in the variant with plowing. Minimization of the impact on the soil during five years led to insignificant changes in the structure of micromycete complexes in the rhizosphere of wheat. The damage of the plants with root rot and leaf diseases upon non-inversive tillage did not increase in comparison with that upon plowing. Wheat yield in the variant with non-inversive tillage was insignificantly lower than that in the variant with moldboard plowing. The application of biopreparations based on the Streptomyces hygroscopicus А4 and Pseudomonas aureofaciens BS 1393 resulted in a significant decrease of plant damage with leaf rust.     

Evaluation of environmental health of the Kolomenskoye Park under anthropogenic pressure from Moscow City

Journal of Soils and Sediments - The purpose of this paper is to evaluate the environmental state of the territory of the famous Russian landscape-architectural museum Kolomenskoye. This park...     

Application of bacterial-humus preparations in the remediation of soils contaminated with diesel fuel

The effect of bacterial-humus preparations on the biological activity of soils contaminated with diesel fuel was studied. The influence of the preparations was judged from the intensity of the CO₂ emissions from the soil, the total number of bacteria, and the structure of the saprotrophic bacterial complex. The ability of bacterial-humus preparations to enhance the biological activity of contaminated soils was shown. The possibility of maintaining target populations of bacteria in the soil for at least two months was proved.     

Inheritance of grain protein content upon crossing covered and hulless barley biological varieties

In a study of F₁ diallel hybrids from crossing covered and hulless barley biological varieties, intralocus overdominance and interlocus interaction of nonallelic genes of the complementary (recessive) epistasis type are revealed in genetic control of grain protein content. It is shown that recessive genes increase protein content. Selection of hulless productive genotypes is preferable in later hybrid generations, starting with F₄–F₆.     

Soils of paleocryogenic hummocky-hollow landscapes in the southern Baikal region

The features of ancient periglacial phenomena are widespread in landscapes lying beyond the modern permafrost zone. The specificity of the paleogeographic conditions in the south of the Baikal region resulted in the formation of paleocryogenic landscapes with hummocky-hollow landforms. The paleocryogenic mounds (hummocks) are of rounded or elongated shape, their height is up to 2–3 m, and their width is up to 20–25 m. They are separated by microlows (hollows). This paleocryogenic microtopography favors the differentiation of the pedogenesis on the mounds and in the hollows, so the soil cover pattern becomes more complicated. It is composed of polychronous soils organized in complexes with cyclic patterns. Light gray and gray forest soils and leached and ordinary chernozems are developed on the mounds; gray and dark gray forest soils and chernozems with buried horizons are developed in the hollows. The soils of the paleocryogenic complexes differ from one another in their morphology, physical and chemical properties, elemental composition, and humus composition. For the first time, radiocarbon dates have been obtained for the surface and buried humus horizons in the hollows. The results prove the heterochronous nature of the soils of the paleocryogenic landscapes in the south of the Baikal region.     

Successful transmission of a retrovirus depends on the commensal microbiota

To establish chronic infections, viruses must develop strategies to evade the host's immune responses. Many retroviruses, including mouse mammary tumor virus (MMTV), are transmitted most efficiently through mucosal surfaces rich in microbiota. We found that MMTV, when ingested by newborn mice, stimulates a state of unresponsiveness toward viral antigens. This process required the intestinal microbiota, as antibiotic-treated mice or germ-free mice did not transmit infectious virus to their offspring. MMTV-bound bacterial lipopolysaccharide triggered Toll-like receptor 4 and subsequent interleukin-6 (IL-6)-dependent induction of the inhibitory cytokine IL-10. Thus, MMTV has evolved to rely on the interaction with the microbiota to induce an immune evasion pathway. Together, these findings reveal the fundamental importance of commensal microbiota in viral infections.     

The humus status of brown forest soils and its changes upon intensive tea growing in the subtropical zone of Russia

Changes in the humus status of acid brown forest soils used for tea growing have been studied in a long-term stationary experiment after 20 years of the application of mineral fertilizers in increasing doses. It is shown that long-term tea growing has resulted in a reliable increase in the humus content within the upper cultivated horizon (Ap, 0–40 cm) at the expense of the nonhydrolyzable fraction of humus (humin) and the first fractions of humic and fulvic acids. The fractional composition of humus has changed against the background of a stable fulvate type of humus (Cha/Cfa < 0.5). The portion of the first fraction of humic and fulvic acids in the total amount of humus has increased, as well as the portion of the first fraction of humic acids in the total amount of humic acids. These changes are due to the enhanced humification of plant residues with a parallel decrease in the contents of the second (Ca-bound) and third (bound with clay and stable sesquioxides) fractions of humic substances.