2024, Vol. 22, Special Issue 1

Selle kollektsiooni püsiv URIhttp://hdl.handle.net/10492/9343

Sirvi

Nüüd näidatakse 1 - 4 4

Influence of petroleum products on the state of microbiocenosis of soil during short and medium terms of pollution
(Estonian University of Life Sciences, 2024) Malynovska, I.; Bulgakov, V.; Olt, Jüri; Rucins, A.; Estonian University of Life Sciences. Institute of Forestry and Engineering
Bioremediation by autochthonous microbial communities is currently considered the main and most environmentally secure way how to remove petroleum products from contaminated soils. To study the possibilities to control the processes of biodegradation of aviation kerosene by indigenous communities of the soil together with plants and in the presence of a cometabolite (glucose), a model experiment was carried out with concentrations of aviation fuel from 0 to 20%. Soil without the addition of petroleum products served as reference. The state of the microbial community was studied 1 and 21 days after the addition of the petroleum products. It has been established that the soil contamination with petroleum products within one day leads to quantitative and qualitative changes in the state of the microbial cenosis, and the phytotoxicity of the soil significantly increases. At low concentrations of the petroleum products (1%) the occurrence of microbiological processes in the soil slows down, and at high concentrations (20%) they intensify. It has been shown that an increase in the number of polysaccharide-synthesising bacteria increases not only the absolute amount of degraded petroleum products from 0.240 to 1.88 g kg-1, but also their relative share from 6.33%. Growing plants and adding easily accessible substrates to the soils contaminated with petroleum products ensures more active destruction of pollutants (by 63.6 and 45.5%, respectively) compared to the soils without phytocenosis and the addition of exogenous substrates.
Investigation of microbiological processes during long-term storage of grey forest soil samples
(Estonian University of Life Sciences, 2024) Malynovska, I.; Bulgakov, V.; Rucins, A.
Investigation of a decrease in the viability of microorganism cells in the soil samples, stored for a long time in an air-dry state, has both theoretical and practical significance since in agrochemistry and the soil science it is a custom to store the soil samples for many years and decades, taking it as an axiom that the properties of these samples remain unchanged. To find out what are the patterns of survival of microorganisms of various ecological-trophic, functional and systematic groups, their viability was studied in samples of gray forest soil, stored for 32 months in an air-dry state. It has been shown that the number of microorganisms of most groups decreases by 42–94 times, the number of polysaccharides-synthesizing microorganisms decreases maximum- by 3,993–18,210 times, depending on the agricultural practices, used in a stationary experiment. the number of spores and cysts decreases. The microorganisms which have the least decrease in the number of colony-forming units of micromycetes and Azotobacter as groups that have forms of surviving unfavourable conditions during storage are spores and cysts. In addition, the physiological and biochemical activity of micromycetes decreases significantly, compared to their activity in the original (initial) fresh soil. During storage the number and share in the total number of melanin-synthesizing micromycetes sharply decreases from 65.8–94.6% to 2.48–5.17%. When storing soil in an air-dry state, the rate of decline in the number of microorganisms depends on the functional affiliation of the group and on agrotechnical techniques that were previously used in the stationary experiments: liming, application of mineral fertilizers, ploughing in the by-products of the predecessor crop in the crop rotation, and the biomass of the sideral crop. The organic matter, ploughed into the soil, promotes the survival of ammonifiers, mineral nitrogen immobilizers, Azotobacter and polysaccharide-synthesizing microorganisms. Ploughing in of crop by-products reduce the number and proportion of melanin-synthesizing micromycetes. Verification of the obtained data, using long-term stored soil samples, is not permissible since microbiological processes occur in the soil during which the soil microbiota consumes the macro- and microelements, present in it, organic and organomineral complexes, including humus.
Resistance of the soft winter wheat varieties to pests and their productivity in the northern forest-steppe zone
(Estonian University of Life Sciences, 2024) Polishchuk, S.; Holyk, L.; Havryliuk, N.; Kuzmenko, L.; Shtakal, M.; Tkachenko, N.; Bulgakov, V.; Ivanovs, S.; Rucins, A.
There are highlighted the results of research in order to determine the field and laboratory resistance of the winter wheat varieties in a competitive variety testing at the National Scientific Centre Institute of Agriculture of NAAS (2016–2020) against pests, and the level of their productivity is assessed. Among the studied varieties of winter wheat, varieties with complex resistance were found: to cereal aphids, wheat thrips powdery mildew and brown leaf rust - variety Efektna; to cereal aphids, wheat thrips and leaf rust - varieties Polisianka, Pyriatynka, Krasunia Poliska, Vodohrai, Kesariia Poliska, Myroliubna, Romanivna, Pamiati Hirka, and standard Lisova Pisnia St. When varieties were grown without the use of fungicides, insecticides and growth regulators, their yield varied over the years from 2.99 t ha–1 to 10.71 t ha–1. The best varieties of soft winter wheat in terms of their productivity were identified in the northern Forest - Steppe zone, which are included in the State Register of the plant varieties, suitable for distribution in Ukraine - Kesariia Poliska (7.67 t ha–1), Pyriatynka (7.10 t ha–1), Myroliubna (7.08 t ha–1), Merezhka (6.77 t ha–1), Kraeivyd (6.71 t ha–1), Pamiati Hirka (6.61 t ha–1), Polisianka (6.51 t ha–1) and Efektna (6.36 t ha–1). Consequently, with proper selection of the winter wheat varieties, it is possible to significantly limit the harmfulness of pests and diseases, to reduce the amount of the used pesticides, to increase the grain productivity, and to improve its commercial and seed quality.
Seasonal sequestration capacity of chernozem under different agrotechnological impacts in agrocenosis
(Estonian University of Life Sciences, 2024) Bulgakov, V.; Gadzalo, I.; Pascuzzi, S.; Demydenko, O.; Holovach, I.; Ihnatiev, Ye.; Olt, Jüri; Estonian University of Life Sciences. Institute of Forestry and Engineering
The soil's sequestration capacity is primarily determined by the fine-dispersed fraction of the soil and strongly influences the properties and fertility level of the soil. To assess the sequestration capacity of C-CO2 humus in soil formation and fertility of typical chornozem (black soil), to identify the causes, rates, existing limits of the sequestration capacity decrease, it is important to study the seasonal dynamics of qualitative and quantitative indicators of humus state in time depending on the method of tillage and fertilization in agrocenoses of short rotation crop rotations in the central part of the Forest-Steppe region of Ukraine. During the research, a stationary field experiment was conducted to study the influence of methods of soil cultivation and fertilizer application on the sequestering capacity of chornozem. Laboratory studies were conducted to determine the content of humus and to calculate the seasonal reserves of absorbed carbon and phosphorus and to model the absorption capacity of chernozem. When processing with chisel plows and applying fertilizers, the increase in the C-CO2 reserve during the April-July period was +21 t ha-1 (0–0.2 m) and +36 t ha-1 a (0–0.3 m). Under moldboard plowing, the growth tended to increase by 1.52 times (0–0.2 m) and 1.25 times (0–0.3 m), but occurred at a lower quantitative level, and in the period July-September, the change in the humus C-CO2 stock was insignificant, indicating the predominance of C-CO2 sequestration processes in the summerautumn period with chisel plowing. With chisel plowing, the reserve of labile organic substances (LOS) in April exceeded the stock for plowing in the thickness of 0–0.3 m by 4.34–7.67 times (without fertilizers), 1.5–2.76 times (with fertilizers); in July - by 4.59–8.90 times (without fertilizers) and 1.32–3.16 times (with fertilizers); in September - by 4.52–4.04 times (without fertilizers) and by 1.11–1.93 times (with fertilizers), and the C-CO2 stock of the LOS compared to fallow land under chisel plowing without fertilizers in April, July, and September was 1.59–1.78 times, 2.31–3.29 times, and 1.4–1.78 times higher, and under fertilization - by 1.99–2.0, 1.86–4.50, and 1.7–2.6 times, respectively, depending on the seasons. Under fallow land maintenance, the seasonal dynamics of the C-CO2 stock of the LOS is subject to the seasonal dynamics of Porg(LOS). A direct strong correlation was found at the level of R = +0.89 ± 0.02; R2 = 79. In the period April-July, the decrease of Porg(LOS) stock in the thickness of 0–0.2 m was found to be 1.15 times, and in the thickness of 0–0.3 m - 1.1 times. From summer to autumn, the stock of Porg(LOS) was restored, and the stock in the thickness of 0–0.3 m increased by 1.10 times. Conclusions. Trends in C-CO2 stocks of humus and LOS indicate that in the series plowingchiseling-fallow land, the cyclicality index under chisel plowing was closer to the value of the seasonal cyclicality of fallow land than the seasonal cyclicality under plowing, which indicates the restoration of the CI. Trends in C-CO2 stocks of humus and LOS indicate that in the series plowing-chiseling-fallow, the index of cyclicality under chisel plowing was closer to the value of the seasonal cyclicality of fallow land than the seasonal cyclicality of plowing, which indicates the restoration of the ISC. However, the timing of changes in the Porg(LOS) stock indicates that in the series plowing-chiseling-fallow, chisel plowing is directed to fallow land by its seasonal cyclicality. The general regularity of seasonal cyclicality for all parameters of humus condition lies in the fact that a decrease in the values of ISC, as in fallow land or under moldboardless tillage, indicates the ordering of ISC, and an increase in the index of cyclicality to destruction, as under plowing.

Sirvi

Sirvi 2024, Vol. 22, Special Issue 1 Autor "Bulgakov, V." järgi

Tulemused lehekülje kohta

Sorteerimisvalikud