https://agrisp.com/index.php/agrisp <p>The National Academy of Agrarian Sciences of Ukraine publishes a scientific journal "Agricultural Science and Practice".</p> <p>The articles dedicated to the basic and applied researches on soil science, agriculture, crops, livestock, fodder, genetics, breeding and biotechnology, agroecology, radiology, reclamation, processing and storage of agricultural products, economy, innovation are published in this journal .</p> National Academy of Agrarian Sciences of Ukraine en-US Agricultural Science and Practice 2312-3370 https://agrisp.com/index.php/agrisp/article/view/2022_03_01 Aim. To study the impact of different levels of radioactive contamination on the organic matter decomposition and the population development of microbial decomposers of organic matter in soil. Methods. Gamma-spectrometry for the determination of the relative activity of 137Cs and beta-spectrometry for the determination of the relative activity of 90Sr in order to choose the contamination range for the studies; Tea Bag Іndex (TBI), the standard glob- ally accepted method to determine the rate of organic matter decomposition; gas chromatography – to determine the impact of the investigated factors on the formation of the biomass of microorganisms by means of the СО2 production potential; classic microbiological methods, using elective media to estimate the population densities of culturable microbial decomposers. Results. The studies (from April to September 2021) comprised two soils with different radioactive contamination ranges: Range No. 1 in Narodychi district of Zhytomyr region (the village Khrystynivka, 3 sampling points) in the unconditional (obligatory) resettlement zone after the catastrophe in the Chornobyl nuclear power plant (ChNPP) (it has an absorbed dose rate gradient, evaluated for soil microorganisms, from 0.2 μGy/h (at sampling point Narodychi-1: 51,24076°N, 29,21497°E) to 1.57 μGy/h (at sampling point Naro- dychi-3: 51,23815°N, 29,22245°E)), located on the agricultural field, abandoned after the catastrophe and Range No. 2, located on the afforested area, directly bordering the territory of the so-called Red Forest in the ChNPP ex- clusion zone (4 sampling points – the first three points – natural ecosystems, and 4th – pyrogenically transformed territory after fires in 2020) with the absorbed dose rate gradient from 3.7 μGy/h (at sampling point ChEZ-1: 51,38595°N, 30,03035°E) to 84.0 μGy/h (at sampling point ChEZ-4: 51,38231°N, 30,03298°E). The dependence of the studied indicators on the gradient of soil contamination with radionuclides was demonstrated and these are the conditions that the difference is more than 400 times in the values of the ionizing radiation absorbed dose rates formed by radionuclides in soil. In Range No. 1 (on the fallow land), with the increase in the dose rate up from 0.2 to 1.57 μGy/h, there was statistically significant increase of mineralization coefficient and percentage of reduced weight of rooibos tea between the least and most contaminated sampling points), stimulation of the development of micromycetes (by 1.2–2.3 times), cellulose-decomposing bacteria (by 7.1–7.9 times), and ammonifying bacteria (by 1.8–6.3 times) due to a significant increasing the number of colony-forming units in points with higher radio- nuclide contamination and an increase of microbial biomass in soil more than twofold between the least and most contaminated sampling point of Range No. 1.In Range No. 2, in the ChNPP exclusion zone, characterized by low parameters of sod-podzolic soil fertility (humus content from 1.2 ± 0.2 to 0.9 ± 0.1 %, exchangeable acidity from 4.0 ± 0.1 to 5.0 ± 0.7), the number of micromycetes and ammonifying bacteria in soil was one-two orders below the indices of Range No. 1. Micromycetes dominated in the groups of cellulose-decomposing microorganisms. There was statistically significant increase of mineralization coefficient and percentage of reduced weight of rooibos tea with increasing of radionuclide contamination level for the first three plots: ChEZ-1, ChEZ-2 and ChEZ-3 of Range No. 2. Conclusions. In the fallow land of the unconditional (obligatory) resettlement zone, the increase of the radia- tion absorbed dose rate in soil by one order from 0.2 to 1.57 μGy/h does not inhibit the development of microorgan- isms in soil, rather it stimulates their activity and increases their numbers. On poor sod-podzolic soils in the exclu- sion zone of the Chernobyl nuclear power plant, the preponderance of development of micromycetes over bacterial cellulolytics is noticeable. The radioactive contamination affected the development of soil microorganisms and the biological processes in soils not only in the first years after the Chornobyl catastrophe, which has been described in the literature, but has had its influence for rather a long time (for over thirty years after the accident). Among the microorganisms of a saccharolytic mode of organic plant residuals decomposition, the micromycetes dominate. I. Gudkov I. Volkohon V. Illienko M. Lazarev A. Klepko Copyright (c) https://creativecommons.org/licenses/by/4.0 2023-04-20 2023-04-20 9 3 3 17 10.15407/agrisp9.03.003 https://agrisp.com/index.php/agrisp/article/view/2022_03_02 Aim. To study acid-base buffering capacity depending on the intensity of different fertilization systems, including lim- ing, with different doses of CaCO3 in a long-term (55 years) stationary experiment on Albic Stagnic Luvisol (light grey forest surface-gleyed soil). This study should serve as a basis for the restoration and protection of fertility and yield and preservation of ecological restorative functions of this soil type. Methods. Field stationary experiment, using monitoring, laboratory-analytical and statistical-mathematical methods. Results. It was found that after 35 years of a seven-field crop rotation the exclusion of the intensive crops of sugar beet, potato and one winter wheat, in combina- tion with low (2.5 time less) mineral fertilization levels, contributed to an increase in resistance to acidification over the next 20 years from 5.53 to 7.48 points (using a 100-point scale) with a simultaneous increase in soil рНКСl from 3.77 to 4.12. Organo-mineral fertilization (N65P68K68 + 10 t manure/ha of crop rotation area) and periodic application of CaCO3 by hydrolytic acidity (6.0 t/ha) and an optimal dose of lime (2.5 t/ha CaCO3) increased pH buffering over these 20 years in a four-field rotation. The general evaluation index of buffering was 21.8–21.9 points, exceeding the virgin soil by 1.9 to 2 points. In the control variants without the use of fertilizers the general evaluation index of buffering was 14.3 ± 0.3, and the coefficient of buffer asymmetry was the highest – 0.646 ± 0.013, which under these conditions indicated the danger of soil losing its ability for self-regulation and self-healing. Conclusions. The resis- tance of Albic Stagnic Luvisol to acidification increased most in the combined application of N65P68K68 and 10 t/ha manure, together with an optimum calculated dose of lime in a 4-year crop rotation. An optimal dose of CaCO3 (2.5 t/ha) and organo-mineral fertilizing system in a 4-year crop rotation improved the soil buffering capacity of the acid shoulder by 2.45 points compared to the mineral fertilization system. To support a determination of acid-buffering effects graphic charts representing pH buffering capacity proved to be useful and could be instrumental in diagnostics and optimization of the acid-base regime for acid forest soils in general. Yu. Olifir A. Habryel T. Partyka O. Havryshko G. Konyk N. Kozak V. Lykhochvor Copyright (c) https://creativecommons.org/licenses/by/4.0 2023-04-20 2023-04-20 9 3 18 28 10.15407/agrisp9.03.018 https://agrisp.com/index.php/agrisp/article/view/2022_03_03 Background. Cryopreservation of spermatozoa with the best morphofunctional characteristics may allow their use for assisted reproductive technologies in goat breeding throughout the year to effectively increase livestock. Aim. To evaluate the influence of seasons on morphological and morphometric characteristics of fresh and cryopreserved goat sperm. Methods. The ejaculate samples of three sexually mature bucks of the Saanen breed were obtained during the breeding and non-breeding seasons. To assess the morphological characteristics, the smears of sperm were stained and then visualized under a light microscope with a magnification of ×1,000. For morphometric measurements, sperm micrographs were taken and analyzed using the ImageJ software. The cryopreservation of sperm was performed in a medium with 10 % glycerol and 20 % egg yolk. The samples were thawed in a water bath, then the morphological and morphometric characteristics of the cells were evaluated. Results. After the cryopreservation, the number of sperm with abnormal morphological structures was significantly higher compared to fresh sperm, both in the breeding and non-breeding seasons (p ≤ 0.05). After the cryopreservation, the length and width of the head decreased significantly (p ≤ 0.05) compared to the corresponding sperm sizes before the cryopreservation. Analyzing the morphological char- acteristics of the tail part, we revealed the fact of its reduction after the cryopreservation, probably due to twisting, loop formation, and detachment of its part. Conclusions. It was found that in the non-breeding season, the number of spermatozoa with damaged morphological structures increases, compared to the breeding season, which must be taken into account when using reproductive technologies. The morphological and morphometric characteristics of Saanen buck spermatozoa change after the cryopreservation, regardless of the season, which indicates the need to choose the fertilization tactics that will ensure the selection of spermatozoa without any morphological abnormalities. A. Bogdaniuk M. Petrushko Copyright (c) https://creativecommons.org/licenses/by/4.0 2023-04-20 2023-04-20 9 3 29 35 10.15407/agrisp9.03.029 https://agrisp.com/index.php/agrisp/article/view/2022_03_04 Aim. To study the mutual relations between different soybean cultivars and two Bradyrhizobium japonicum strains after mixed inoculation, to evaluate the impact of the introduced microorganisms on the local rhizobial communities in soil, the formation and functioning symbiotic systems, and productivity of soybean. Methods. Microbiological and serological methods; field experiment, gas chromatography and mathematical-statistical methods. Results. A small- plot field experiment demonstrated that the use of a mixture of B. japonicum 46 and B. japonicum КВ11 strains pro- moted a more even distribution of the local and introduced rhizobia in the nodule populations of 12 soybean cultivars of different geographic origin. There was no domination of particular strains in the nodules, and the symbiotic systems formed were more balanced than the control without inoculation. After inoculation of the above-mentioned mixture, in most cultivars there was a considerable increase in the number of nodules (10–45 % more) and their mass (11–86 % increase). There was also an increase in the level of symbiotic nitrogen fixation with 1.2–4.2 times and an increase in the weight of grain per plant by 6–29 % (depending on the cultivar). The efficiency of a mixture of B. japonicum 46 and КВ11 strains in a preparation Rizogumin was confirmed in extensive field trials with soybean on an area of about 60 thousand ha in different regions of Ukraine. In the background of the local populations of the soybean nodulating bacteria in the areas, the application of the formulated mixture of the two rhizobia strains ensured a stable increase by 15–33 % in the soybean yield as compared with the control without the inoculation. Conclusions. A novel approach was investigated, which lies in the application of a mixture of B. japonicum 46 (genetic group USDA 6) and B. japoni- cum КВ11 (genetic group USDA 123) strains for different soybean cultivars inoculation. Combining these two strains and their introduction into agrocenoses ensured the formation of a balanced symbiotic systems (without clear domina- tion of some strains in the nodules). This was expressed in an intensified nodulation, symbiotic nitrogen fixation, and increased yield of different cultivars of soybeans by 15–33 % as compared to the control (without inoculation). D. Krutylo Copyright (c) https://creativecommons.org/licenses/by/4.0 2023-04-20 2023-04-20 9 3 36 48 10.15407/agrisp9.03.036 https://agrisp.com/index.php/agrisp/article/view/2022_03_05 Aim. To identify mutations and evaluate the mutation frequency in Nigella damascena L. cultivars (cvs) Bereginya and Charivnytsya (M2 and M3 generation), following treatment of their seeds with ethyl methanesulfonate (EMS), nitrosomethylurea (NMU) and a new derivative of dimethyl sulfate, DG-2. Methods. Treated Nigella seeds of two cvs with the mutagens for 6 and 16 h and in concentrations of 0.01 and 0.5 % for EMS and NMU and 0.05 and 0.5 % for DG-2. Results. A wide range of mutations (59 types) was obtained, that was divided into six groups: five groups with changes in the morphological type and one group with changes in the physiological type. Among the detected mutations, there were both previously known mutations and those obtained in this culture for the first time. The high- est mutation frequency (30 %) affecting synthesis of chlorophyll and structure of stem, shoots and leaves and 20 % for physiological features, was registered for NMU at 16 h and 0.05 % in cv. Bereginya. However, this NMU concentra- tion appeared to be lethal for cv. Charivnytsya. Conclusions. The new mutagen DG-2 proved to be most effective for inducing mutations in the corolla petal color of nigella, namely 4.0 at a 0.5 % concentration of the mutagen and 16h exposure for cv. Bereginya and 4.0 % at the same concentration and exposure for cv. Charivnytsya. DG-2 caused a substantial number of mutations in all six mutation groups affecting morphological and physiological traits. The clas- sic mutagen EMS was also effective across the spectrum of mutation groups in our study; however, it caused mutations at a lower frequency. The maximum mutation frequency under influence of EMC at a concentration of 0.05 % and an exposure of 16 h in cv. Bereginya was 11.0 %, and in cv. Charivnytsya 8.0 %. For all three mutagens used, an increase in the concentration of the active substance and of exposure time led to an increase in the mutation frequency in N. damascena plants. We will select mutants with economically valuable traits, such as tall, lodging-resistant plants and early maturing ones, for further work on the development of new cultivars of N. damascena for industrial cultivation. Yu. Gubanova Copyright (c) https://creativecommons.org/licenses/by/4.0 2023-04-20 2023-04-20 9 3 49 63 10.15407/agrisp9.03.049 https://agrisp.com/index.php/agrisp/article/view/2022_03_06 Aim. To study the efficiency of inoculating spring barley with Azospirillum brasilense 410. Methods. 1) A field ex- periment on turfpodzolic sandy soil with different mineral fertilization regimes; 2) A greenhouse experiment on sand as substrate, with isotope dilution analysis using 15N; 3) A lysimetric experiment in a stationary lysimetric installation. Furthermore, chromatography to determine nitrogenase activity of bacteria in the root zone of plants, agrochemical, and statistical methods. Results. Under field conditions, the inoculation with A. brasilense 410 promoted a significant increase (37–103 %) in the nitrogenase activity in the “soil-plant” system without any mineral fertilization and (espe- cially) where N60P60K60 was used. A high fertilizer level (N120P120K120) lead to a long-term inhibition of the nitrogenase activity. In both cases (plants with and without inoculation with A. brasilense 410) this fertilization level showed an increase in the nitrogenase activity only at the end of the vegetation period. The highest increase in yield (0.7 t/ha, 27 %) in yield following A. brasilense strain 410 inoculation, occurred in plots with N60P60K60 fertilization; the least increase in yield (0.33 t/ha, 16.5 %) was observed in plots receiving no fertilizers. The pre-sowing inoculation led to an increase in the protein content of 0.3–1.0 % in the barley grain, especially when receiving high fertilization levels, enhancing its value for the use in cereals and feeds, but decreasing its value for its use in brewing. The green- house experiment with 15N established an increase 77.1 % in the nitrogen intake into the plants due to the activation of the nitrogen-fixation process and enhanced 29.5 % nitrogen consumption from fertilizers. The lysimetric studies demonstrated that inoculation of spring barley cv Nosivsky with A. brasilense 410 limited the vertical migration and leaching of nitrogen by 27–30 %, potassium by 13–30, calcium by 32–51 %, manganese by 33–100 %, and water-sol- uble organic matter by 46–75 %. Conclusions. The pre-sowing inoculation of spring barley cv. Nosivsky seeds with A. brasilense 410 intensifies nitrogen consumption by plants within 29.5 % due to active nitrogen-fixation and a better utilization of N from mineral fertilizers. The barley yield increase with 0.7 t/ha was in our limited experiment, using one cultivar roughly equivalent to the increase after mineral fertilization with N60P60K60. Thus, pre-sowing inoculation with A. brasilense 410 may lead to substantial reduction of the use of mineral fertilisers in practice. V. Volkogon A. Moskalenko S. Dimova K. Volkogon L. Potapienko Copyright (c) https://creativecommons.org/licenses/by/4.0 2023-04-20 2023-04-20 9 3 64 75 10.15407/agrisp9.03.064