Vestnik of the Russian Agricultural Science

The research was conducted in 2021–2025 on the basis of I.A. Bunin Yelets State University under the conditions of model experience. In terms of physical parameters, dark gray forest soil turned out to be more moisture-intensive and hygroscopic than sod-podzolic soil. According to agrochemical indicators, dark gray forest soil differed from sod-podzolic soil in more favorable properties: less acidic reaction of the medium, more humus, total nitrogen, mobile phosphorus, exchangeable potassium and especially exchangeable calcium – 2.5 times. By the 4th year of growth, the appearance of a young apple seedling of the Boiken variety showed that growth was faster on dark gray forest soil. The 4-year-old apple seedlings grown on dark gray forest soil were significantly taller, had a larger stem diameter, and a longer length of annual terminal growths. The number of leaves per 1 terminal apple tree growth and the average leaf area did not depend on the type of forest soil. The water retention capacity of the leaves of apple seedlings grown on dark gray forest soil was significantly higher than that of plants grown on sod-podzolic soil. The water content in the leaves of the seedlings was significantly higher in plants grown on dark gray forest soil.

The study was conducted to evaluate the effectiveness of using bottom sediments from the impact zone of a trout farm in the Republic of Karelia for germinating seeds of common oats (Arkhan variety), winter rye (Falenskaya 4 variety), oilseed radish (Tambovchanka variety), and common peas (Jackpot variety). The experiment was conducted in laboratory conditions according to a standard methodology and with the following protocol: control – distilled water (DW); variant 1 – diluted with water in a ratio of 1:1 (DBS); and variant 2 – original bottom sediments (BS). The effect of bottom sediments was assessed based on seed germination and seedling morphometric parameters (root length, seedling height and weight). It was found that the use of bottom sediments characterized by increased potassium and calcium content increased seed germination and germination rates. Representatives of the Poaceae and Brassicaceae families responded more readily to treatment with bottom sediments than legumes. In oilseed radish, BS and DBS treatments increased laboratory seed germination by 10.5 and 12.2%, respectively, relative to the control (DW – 75.8%). In the experimental variants, the linear growth of R. sativus roots increased by 3.1–3.4 times, and that of S. cereale seedlings by 1.7 times, compared to DW (24.0 and 38.5 cm, respectively). Along with the increase in morphometric parameters, seedling weight increased, particularly in A. sativa due to stimulation of root growth (in BS and DBS – 0.207 g each, relative to DW – 0.148 g). The accelerated germination of oats, rye, and oilseed radish seedlings is likely also related to the chemical composition of their seeds and the rapid hydrolysis of reserve nutrients – carbohydrates and fats. The reduced rate of germination and growth of pea seedlings may be due to the fact that the hydrolysis substrate in the seeds is storage proteins, which degrade more slowly than carbohydrates. To reduce the negative impact of accumulating bottom sediments, including natural biogenic components and fish farm waste, on lake ecosystems in the northern taiga zone of the Republic of Karelia, it is promising to use them as organic fertilizers for agricultural production.

The forage production in Karelia is limited by a narrow range of cultivated species and crops. In recent years, there has been increasing interest in variable alfalfa (Medicago varia L.), a promising crop that possesses long productive longevity and can thrive under northern farming conditions, despite several limiting factors such as the possibility of late spring frost and early autumn frost, high soil acidity, and a short growing season. Overcoming these barriers is possible through the selection of varieties capable of ensuring stable yields of forage mass and high productive longevity. The article presents the results of a comparative study of the varieties Vega 87 (control), Pastbishnaya 88, Lugovaya 67, Selena, Agniya, and Taisia under the conditions of the Republic of Karelia. According to multi-year data, the variety Agniya significantly stands out in terms of productivity, exceeding the control by 1.5 t/ha and the other varieties by 1.2—1.7 t/ha of dry mass.

This study presents a comparative assessment of two main methodological approaches for the detection and quantification of the phytopathogenic fungus Colletotrichum nymphaeae in soil: the cultural method using nutrient media and real-time PCR. The main purpose of the work was to evaluate and compare the sensitivity and practical limitations of these methods in relation to different soil types. The cultural method was optimized by testing various degrees of dilution of soil suspensions and comparing the efficiency of three nutrient media. In parallel, DNA extraction from contaminated soil using a commercial kit was tested, followed by identification using real-time PCR with specific primers. The results demonstrate that the efficiency of the cultural method depends on both the soil type and the selected nutrient medium. The PCR method showed significantly higher sensitivity, allowing for the detection of the pathogen at concentrations below the detection threshold of the cultural method. However, it is sensitive to the inhibitory effects of organically rich soils. The obtained data emphasize the need for an integrated approach. This study provides practical recommendations for monitoring C. nymphaeae, which contributes to improving the accuracy of phytosanitary diagnostics and the development of plant protection strategies.

Based on analyses conducted in the Central Districts Republic of the Sakha (Yakutia), it was found that wild black currants thrive in neutral and slightly acidic soils with sufficient humus. In the Vil'yui Districts, currants thrive in soils with a higher humus content. Wild black currants thrive in slightly acidic and slightly alkaline soils with sufficient humus, with humus content in the 10–20 cm horizon being only 1.12 times lower than in the upper horizon. Soils in the Amginsky District are less rich in water-soluble phosphorus and potassium salts, while the highest concentrations of these salts are found in floodplain soils in the 0–10 cm horizon in the Namsky District. The characteristic feature of the soils where black currants grow in the Nуurbinsky and Verkhneviyusky districts is the extremely low content of water-soluble potassium salts (from 118–160 mg/kg), but the high content of humus (on average 5.5%), as an indicator of the high intensity of the vital activity of soil microorganisms, suggests that this compensates for the lack of limiting salts.

The results of studying the occurrence of afterbirth retention in cows on dairy farms in the south of the Far East are presented. As a result of the research, 1893 calvings were recorded, retention of the afterbirth was registered in 273 individuals (14.4%). Including in the summer-autumn period in 12.1% of cows, and in the winter-spring period – in 15.4%. The assessment of the reproductive ability of cows revealed the negative consequences of this pathology on all the studied indicators. If on average for the entire number of cows the period from calving to the first heat was 65.2 days, before fertilization – 112.2 days. then for the group of cows with afterbirth retention – 70.6 and 119.4 days, respectively, and the number of inseminations for conception increased from 1.98 to 2.16 or by 9.1.

The study was conducted to assess the influence of the inbreeding coefficient (Fx) (n = 207), the level of homozygosity (Ca) (n = 207) and genomic inbreeding (FROH) (n = 78) of Holstein and Black and White breeding bulls on the parameters of their own sperm production. With an increase in Fx, a tendency towards an increase in the average ejaculate volume is observed, accompanied by a decrease in the concentration of spermatozoa in the semen, which is especially noticeable when comparing the first group (1.43 billion/ml) with the subsequent ones (up to 1.3 billion/ml). The multiple correlation coefficient is 0.217, and the determination coefficient is 0.047, which indicates a moderate relationship between these parameters. Statistical significance at p = 0.043 confirms the presence of a real influence of inbreeding on this parameter. Calculation based on STR markers shows that the average ejaculate volume tends to increase with the inbreeding level (from 4.46 ml to 5.19 ml); the sperm count in the ejaculate varies within the range of 6.23-7.06 billion; sperm concentration shows moderate fluctuations (1.29–1.41 billion/ml); semen activity remains consistently high (about 8 points). Thus, this indicates that even at high homozygosity levels (up to 77%), the main parameters of semen quality remain within the normal range. Analysis of variance shows that the sperm count in the ejaculate demonstrates a statistically significant dependence on the homozygosity level. According to SNP markers, sperm concentration has a very weak correlation with the homozygosity level (R = 0.117), with no statistical significance at all (p = 0.792). The average ejaculate volume shows a moderate correlation (R = 0.249), but statistical significance was not achieved (p = 0.187). Sperm activity demonstrates an extremely weak relationship (R = 0.150) at p = 0.635. Total sperm count shows a moderate relationship (R = 0.189), but also without statistical significance (p = 0.435). Across all samples, a reliable difference was noted between the studied groups according to Cochran's g-test using the G-test and the Bartlett's test at a significance level of α = 0.05. The reproductive potential of stud bulls was noted to be resistant to moderate levels of inbreeding. This allows for a more flexible approach to breeding issues, taking into account not only the degree of inbreeding, but also other selection parameters.