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Features of determining the subspecies status of honey bees (Apis mellifera) based on morphometric wing indicators of drones

As of today, in Ukraine, there are no opportunities to conduct genetic research on a sufficient scale to identify the composition of the genomes of honey bees. Wing morphometrics of drones is a readily available alternative for obtaining information about the approximate composition of DNA. The goal of the work was to formulate the principles of the main stages of research and illustrate the procedure for obtaining morphometric data, methods of their processing, and possibilities for interpreting the obtained results. In the package of statistical data processing application programs Statistica, the classification of 2,147 drone wings obtained from 6 apiaries of Zhytomyr, Mykolaiv, and Kyiv regions was carried out according to eight indices: Ci, Dbi, Disc.sh, Pci, Ri, Ci.3, Ci.2.1, and Ci.2.2. We propose a method for obtaining morphometric wing standards of bees based on studying a significant number of bee colonies from various apiaries in specific regions of Ukraine. Using a two-stage methodology, three datasets were formed and recommended for use as standards: one for the local population of Ukrainian bees and two for populations of the A.m.mellifera subspecies distributed in the Polissia region. We analyzed the reliability of results in determining the taxonomic affiliation of bees was analyzed. Using the example of a single bee colony, a detailed procedure is demonstrated to identify taxonomic affiliation through utilization of the obtained standards. It has been demonstrated that in case of reliable identification of standards belonging to specific subspecies, it is possible to predict the likely composition of chromosomal sets in the genomes of drones, queens, and worker bees partially corresponding to the wing phenotype.

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Normalised difference moisture index in water stress assessment of maize crops

Remote sensing is a promising technique for better management of water resources in agriculture through improvement of dynamic control and operational scheduling on irrigated croplands. The main goal of this study was to identify the possibilities of application of the normalised difference moisture index (NDMI) to water stress monitoring in maize crops, and to determine the relationship between the index and soil moisture content. The study was carried out in 2019–2021 in the experimental fields of disturbed maize, cultivated on dark-chestnut soils in the Southern Ukraine at the NAAS Institute of Climate-Smart Agriculture. The crop cultivation technology was common for the conditions of the steppe zone of Ukraine. Actual soil moisture content was determined by gravimetric method in the pre-sowing and post-harvest period. The NDMI values were calculated using cloudless aerospace images from the satellites Landsat 8, Sentinel-2, and MODIS with 250 m resolution. It was revealed that the seasonal NDMI dynamics perfectly reflected the water-supply conditions of the disturbed maize, and could be used for operational monitoring and scheduling of irrigation. The parameters of the water-supply conditions were determined in 2021, which was the wettest year of the study: the cumulative seasonal NDMI reached 1.71, while the highest water stress was recorded in the driest year, 2020, – the cumulative NDMI was 0.15. Additionally, there was a moderately strong negative correlation between NDMI and soil moisture content, and the coefficient of determination was 0.62. The linear regression models, developed to predict soil moisture content in the 0–100 cm layer depending on the NDMI values, had good fitting quality and reasonable accuracy, but they required further calibration and extension of the initial dataset to provide more robust and reliable results for practical implementation. Based on the results of the study, spatial NDMI could be considered a good and reliable tool for improving irrigation water management. Further studies should focus on the practical implementation of the NDMI-based model of moisture-content estimation, as well as on the possibilities of the index usage for mapping irrigated lands.

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Influence of cultivation methods on the soil aggregate state in the context of weed development in winter wheat plantations

Weed control in winter wheat crops is an important issue. There is a risk of increasing populations of certain weed species that are resistant to some of herbicides used for winter wheat crops. This could be controlled by a combination of agronomic, mechanical, chemical, and biological methods. After introducing winter wheat into the rotation and improving tillage, the weediness of regular black soils with perennial root and emerged weeds were significantly reduced. The formation of nodal and rudimentary roots had a significant effect on the productivity of winter wheat under different soil moisture conditions. The highest yield of winter wheat was obtained when sown at the optimum time, with higher stem density and ear productivity due to better grain fullness. We studied what effects did the tillage methods have on the aggregate state of the soil in relation to weed development in winter wheat crops, finding that the structural and aggregate composition of the soil played an important role in winter wheat crops, influencing both the development of the crop root system and the water-physical balance of the chernozem, as well as naturally influencing the course of erosion processes in the experimental plots, and having a universal dynamic in terms of adaptation of aggregation and disaggregation processes. Prolonged mechanical stress on soil can cause destruction of its structure. For instance, continuous ploughing or moldboardless tillage with little or no manure application may permanently reduce soil fertility by increasing humus mineralisation. Subsequently, these factors may cause a significant decline in the soil's structural and aggregate composition, resulting in larger amounts of dusty particles smaller than 0.25 mm and cloddy particles larger than 10–12 mm. The soil's structural condition before sowing winter wheat in early September, on average for 2011–2016, indicates increased dispersion of the tilth layer (0–10 cm) in the experimental variants where shallow disc tillage of 10–12 cm was applied. Increase in the number of clods larger than 10 mm in the areas where moldboardless tillage had been applied can be attributed to significant soil drainage. The soil's aggregate state was rated as good, with 8.7% in the 0–10 cm soil layer and 1.7% of clods > 10 mm in the 0–30 cm layer. In 2014–2016, it was rated as satisfactory, with 7.4% and 9.8% of clods > 10 mm, respectively. Shallow disc cultivation resulted in slightly worse indicators: 6.6% and 8.3% of clods > 10 mm in soil layer 0–10 cm and 0–30 cm, respectively, in 2011–2013; and 7.2% and 6.9% of clods > 10 mm, respectively, in 2014–2016. In general, the parameters of optimal structural condition were positive. The tillage method used had a considerable effect on weed growth and development, particularly for those with a root and rhizome structure. It also affected the prevalence and development of pests and diseases in winter wheat. Agrotechnical methods of weed control do not guarantee complete destruction of weeds. Mechanical moldboardless tillage to the depth of 14–16 cm and disc tillage to the depth of 10–12 cm left the fields with 4.1 to 8.8 annual weeds per square meter and 1.3 to 3.3 specimens of harmful root weeds such as Convolvulus arvensis, Lactuca tatarica and Cirsium arvense. Mechanical moldboardless tillage to the depth of 14–16 cm and disc tillage to the depth of 10–12 cm left the fields with 4.1 to 8.8 annual weeds per square meter and 1.3 to 3.3 specimens of harmful root weeds such as Convolvulus arvensis, Lactuca tatarica and Cirsium arvense. Post-harvest residues (4–5 t/ha) can provide almost complete protection against weeds by covering the soil surface. However, pests and diseases may spread more easily due to preservation of fungal spores on the surface of plant residues and preservation of pest larvae in the straw and soil. The distribution of weed seeds in the soil was altered when the rotational tillage of common chernozems in winter wheat cultivation technology had been replaced with energy–saving minimum tillage (shallow flat-cutting disc tillage). This resulted in the concentration of most of the weed seeds (85–90%) in the upper soil layer (0–10 cm).

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Decrease in fertility of typical chernozem due to long-term anthropogenic pressure in grain-beet crop rotations

The saturation of sugar beet rotations under different fertilizer application systems and long-term cultivation induces significant changes in soil properties, leading to decreases in humus content, mineral nitrogen, phosphorus, and potassium. The study was conducted in a stationary multifactorial experiment in grain-beet crop rotations: crop rotation, row-crop, and grain-row crop rotations with the application of 40 t/ha of manure under sugar beets + NPK 100:90:90 and a variant without fertilizers. The paper presents the results of monitoring changes in humus content during each rotation, reduction of humus reserves in the plow layer, and physicochemical and agrochemical soil indicators. In the variants without fertilizers, we observed 0.24–0.41% decline in humus content in all crop rotations during 3 rotations of ten-field crop rotations (30 years). Overall, there occurred 0.89–1.00% decrease over 50 years of anthropogenic influence, equivalent to 31.8–35.7 t/ha, or 23.1–26.1% of initial reserves per hectare. Despite application of 40 t/ha of manure + NPK 100:90:90 under sugar beets, humus loss was 27.5 t/ha in the row-crop rotation and 16.8 t/ha in the grain-row crop rotation. Fertilizer application led to increase in exchangeable and hydrolytic soil acidity. With the application of 6.7 t/ha of manure + NPK 53:42:42 per 1 ha of crop rotation area, there was a tendency towards increase in mineral nitrogen content, mobile phosphorus doubled to 280.1–302.8 mg/kg compared to the variant without fertilizers, and exchangeable potassium decreased regardless of the fertilization system, which was associated with its utilization by plants. Sugar-beet yield increased to 44.76 t/ha in the crop-rotation under the organo-mineral-fertilizer application system, exceeding the spring wheat rotation by 4.63 t/ha and the variants without fertilizers by 2.45–2.72 times. Therefore, the modern fertilizer application system under sugar beets did not ensure stabilization of humus content in the soil and increased its acidity. It is necessary to more broadly use cover crops in crop rotations, incorporate crop residues, and apply biological preparations to improve soil fertility.

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Effect of weeds on pea (Pisum sativum) seed germination

Segetal vegetation should be controlled both during crop growing season and after harvesting. The reason is that undesirable vegetation accumulates a significant mass, one that will later become a threat to the following crop in crop rotation. Mixtures of substances of biogenic origin, called allopathic, are constantly changing subject to abiotic factors and environmental conditions. Therefore, their effects on organisms are characterized by significant variability. According to the biotesting results, we found that allopathically active substances of all experimental weed species had a negative effect on pea seed germination. In the control variant, all seeds germinated in 4 days, but in some experimental variants 2–3% of the seeds were in the phase of swelling. Water extracts from different species and parts of weeds had significant inhibitory effect on the germination of pea seeds and further growth. The water-soluble extracts from the underground organs of perennial weeds such as Elytrigia repens L. and Cirsium arvense L. were particularly strong, leading to 58.2% and 53.1% reduction in the length of the embryonic root. Water-soluble extracts from the leaves of these weeds had slightly lower effects on pea germination, and the lags in root growth were 33.5% and 31.4%, respectively. Extracts from weed stems also inhibited pea germination and had an intermediate effect between the effect of water-soluble extracts from the underground part and leaf blades. The effect of extracts from roots of annual weeds on the length of the germinal root ranged 36.6% in common stork’s-bill (Erodium cicutarium L.) to 13.9% in chickweed (Stellaria media L.). The allopathic effect of the substances from the leaves of chickweed (Stellaria media L.) and potato weed (Galinsoga parviflora Cav.) had the lowest effect on the growth of pea root. The lag of the indicator in the control was 7.2% and 12.9% for the variants.

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Efficacy of growth regulators for maize fields

At the current stage of agricultural development, it is paramount to introduce advanced technologies for maize cultivation. Special attention is required for the use of modern growth regulators in order to ensure stable increase in grain production. To protect maize from stress factors emerging in unfavorable meteorological conditions of the steppe zone (such as drought, high temperatures, negative impacts of pesticides, diseases, etc.), increasing attention is given to the application such physiologically active compounds as plant-growth regulators (PGRs). The experimental studies were carried out in 2021–2023 on the experimental field of the Dnipro State Agrarian-Economic University. The objective of the study was to identify the efficacies of the plant-growth regulators used in different doses on maize. The highest efficacy in the technology of maize cultivation was achieved by treating the maize plants with humates during the phase of 3–5 leaves. This treatment promoted a stable tendency towards growth, resulting in 5–7 cm increase in height (2.1–2.8%), 5–6% increase in leaf surface area, and increases in yield structure (13.6 cm in the cob length (5.1%), 18 grains (3.9%) in cob grain filling, and 29 g (9.1%) in mass of 1,000 grains), compared with the control without growth regulators. Somewhat lower efficiency according to all the aforementioned parameters was demonstrated by coating of seeds. Treatment of the seeds with growth regulators and microbial fertilizers in the phase of 3–5 leaves resulted in 7.3% to 18.7% increase in the yield, indicating their high efficacy, especially in unfavorable weather conditions. Therefore, the greatest gains in the grain yield was seen after using humate 400 g/ha + polyethylene glycol 360 g/ha – 1.08 t/ha; humate 800 g/ha + polyethylene glycol 240 g/ha – 1.19 t/ha; sodium metasilicate 600 g/ha – 1.23 t/ha; Pakt 500 g/ha – 1.23 t/ha; and Peram 100 mL/ha + Vympel PGR 500 g/ha – 1.12 t/ha. That is, of the sixty seven tested combinations of physiologically active compounds, no variant produced a grain-yield increase lower than 0.5 t/ha, and the variants with foliar feeding of the maize demonstrated no clear upward tendency in the yield after the PGRs had been introduced in doses above the norms. Studies of efficiency of the growth regulators and microbial fertilizers for maize confirmed that achievement of maximum grain yield is possible only by optimizing the vital factors at all stages of organogenesis of maize. When climatic elements develop with various amplitudes during a vegetative period, effectiveness of preparations is determined by their ability to enhance tolerance to the environmental stressors.

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Environmental quality assessment of soil as a component of green spaces in parks of the megalopolis

Intensive land degradation occurs under conditions of accelerated urbanization; it is strongly associated with the loss of soil natural capital, primarily animals, plant cover, and biological diversity in general. The creation and functioning of parks, in particular green spaces, in the urbanized areas is an effective mechanism for optimizing the ecological situation within the cities and preventing desertification. The soils of parks are an integral component of green infrastructure; they determine the conditions for the growth and development of both individual plants and green spaces as a whole. The soil buffering capacity actively participates in the mechanisms of implementation of the development and stabilization of soil fertility potentials. The buffering capacity determines the proportion of the soil potential that controls the processes of immobilization (deposition) and mobilization (release, loss) of a particular element of fertility: first of all, mineral nutrients for plant growth, productive moisture, thermal energy in soil, gas composition of soil air, and acidity. We collected soil samples beneath the crowns of trees growing in the territory of the Taras Shevchenko Central Culture and Leisure Park, as one of the largest parks in the city of Dnipro (Ukraine). The soil samples were collected in order to assess the soil acid-base (pH) buffering capacity (pHBC) and determine the direction of microbiological processes in urban soils of the park area afforested with stands from such introduced tree species as green ash (Fraxinus pennsylvanica), black locust (Robinia pseudoacacia), northern red oak (Quercus rubra), tree of heaven (Ailanthus altissima), Kentucky coffee tree (Gymnocladus dioica), and box elder (Acer negundo). The acid-base buffering capacity of the urban soil was determined using the Arrhenius method and estimated according to the buffering area within the acid-base range, calculated using the Simpson formula. Direction of microbial processes in the soil was determined according to the indexes of mineralization-immobilization, pedotrophicity, and oligotrophicity. The output was processed using statistical methods (arithmetic mean and standard deviation were calculated; the difference in the means was found according to the Tukey’s comparison test; interdependencies were determined by linear correlation). We have found significant, strong positive correlations between the pH level of urban soils in the rhizosphere area of the introduced species of park dendroflora and the buffering area within the acid and acid-base (total) range of external influence, as well as a strong negative correlation between pH and buffering area in the alkaline range of external influence. We identified weak mineralization signs according to the ratio of functional groups of microbiota in the studied sites forested with Fraxinus pennsylvanica and Acer negundo.

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Agroecological drivers of winter rye (Secale cereale) yield spatio-temporal variation

The study of yield-limiting factors of rye, a typical European cereal, is a crucial concern today as it significantly impacts global food safety. The objecive of the study was to determine the contribution of agroecological factors, namely bioclimatic variables, soil parameters, and landscape diversity, to the variation of rye yields in the central and northern regions of Ukraine, which is one of the world’s five largest producers of this crop. A symmetric log-logistic model was used to describe the dynamics of rye yields, and the parameters of this model can be used to analyze the spatial dynamics of yields, in particular, such characteristic points of the yield model as: the lower limit of the response (the lowest yield level); the upper limit (the highest yield level); the slope of the response curve in the vicinity of the inflection point, which shows the rate of yield change over time, ED50 – the time required to reach half of the maximum yield growth. In the preliminary principal component analysis, we identified 4 climate principal components and 6 soil principal components. Landscape diversity was assessed based on the Shannon index and distance to the protected areas. The results of the regression analysis revealed a statistically significant relationship between the parameters of rye yield and the identified environmental drivers. Among the rye yield parameters, the highest sensitivity to environmental factors was the upper yield limit (70%), and the lowest was the rate of yield increase (25%). Only the highest rate of yield growth demonstrated liner dependence on the Shannon index. Among the soil factors, the most influential for rye yields was the particle size distribution and especially the sand content. The rye yield parameters were primarily influenced by the variability of the temperature regime throughout extreme periods of the year and contrast in the temperature conditions. The yield parameters of rye were contingent upon the diversity of the landscape cover. The correlation between almost all yield characteristics and landscape-ecological diversity was not linear, leading to the identification of an optimal level of diversity in natural protected areas which results in the best rye yields.

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Importance of pollinator diversity for sunflower seed production

The sunflower (Helianthus annuus Linnaeus) is one of the most important food crops in the world. In modern agroecology, this pivotal plant is deeply intertwined with diverse pollination mechanisms. This study elucidates the multifaceted contributions of various pollinator taxa, delving into their respective efficiencies and behaviors vis-à-vis sunflower reproductive success. The honeybee (Apis mellifera Linnaeus, 1758) plays a central role in sunflower pollination, transferring pollen over large distances, thereby bolstering the genetic diversity of sunflower populations. While sunflowers derive immense benefits from honeybee pollination, they reciprocally offer their pollen as vital nutrition for bee larvae. However, this symbiotic relationship is nuanced, with honeybees occasionally exhibiting selectivity based on sunflower cultivar. While honeybees are paramount, the richness of the ecosystem is further accentuated by the presence of other pollinators, each contributing uniquely to the sunflower’s lifecycle. The foraging fidelity of solitary bees, such as the leafcutter bee (Megachile spp.) and mason bee (Osmia spp.), underscores their indispensable role in cross-pollination. Bumblebees (Bombus spp.) introduce a fascinating "buzz pollination" mechanism, leveraging vibrations to optimize pollen release. Simultaneously, wasps provide functions beyond pollination, serving as biocontrol agents by preying on detrimental pests. Surprisingly, mosquitoes appeared to also be contributors to pollination, especially when traditional pollinators are scarce, with their nocturnal tendencies augmenting pollination continuity. Hoverflies render dual benefits: they aid in pollination and their larvae predate on pests. While butterflies are primarily nectar-oriented, they inadvertently partake in pollen transfer. Moths, through their nocturnal activities, complement pollination. Beetles, often overlooked, act as secondary pollinators. Regrettably, contemporary agricultural practices often disrupt this ecological equilibrium. Pervasive pesticide use and habitat fragmentation imperil these pollinators, underscoring the urgent need for pollinator-friendly approaches. As climate conditions fluctuate, understanding these pollinator dynamics becomes increasingly critical. This comprehensive examination advocates for holistic conservation strategies, targeting sustained sunflower yields and broader ecosystem resilience.

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Скорочення викидів парникових газів шляхом упровадження низьковуглецевих технологій використання земель, порушених гірничими роботами

The climate change is a global environmental problem. Its solution requires thereduction of greenhouse gas emissions, especially CO2, as soon as possible. The developmentand implementation of low-carbon technologies can help in achievement this goal. Disturbedlands, which are a source of environmental pollution, can be used to reduce CO2 emissions. Wepropose to introduce technologies for locating solar and wind power plants on disturbed lands,primarily on mining dumps of overburden. The capacity of such solar and wind power plants canreplace thermal power plants, which generate the main volumes of CO2 emissions. Placing onthe mining dumps of overburden of solar power plants has advantages due to the use of southernexposures of the slopes. The wind power plants on the top of mining dumps of overburden takemore opportunities to use of wind speed by attracting additional height. Mining dumps haveemitted carbon dioxide due to the decomposition of limestone and the spontaneous combustion ofcarbon-containing rocks. Counteraction of CO2 emissions by coating the surface with inert materialsthat block the access of moisture and acid solutions to hazardous rocks is proposed. The useof new technologies for the rehabilitation of disturbed lands through the formation of secondaryecosystems creates opportunities to reduce greenhouse gas emissions. This have avoids additionalCO2 emissions during the operation of machines and mechanisms at the mining–technicaland biological stages of reclamation. Secondary soils able to accumulate carbon in the form oforganic matter up to 11 t / ha for 30–50 years. The study of technogenic soils formation on loess-like loams in the landscape reserves “Vizyrka” (Inguletsky GOK), “Hrushivka” (MarganetskyGOK), “Vershina” (Prosyansky GOK) are have evidenced of this facts. Plant components of ecosystemshave even more opportunities. Secondary vegetation absorbs CO2 from the atmosphereduring photosynthesis, creates the coating of surface of lands disturbed by mining operations.Clover plant group show the greatest ability to accumulate carbon (up to 57 t/ha per year). Theresearch was carried out at the research area of Inguletsky GOK. Our assessment testifies that theintegrated application of the above technologies will reduce emissions in Kryvbas by 95 milliontons of CO2 per year. The work was carried out under the target program of the National Academyof Sciences of Ukraine “Scientific and technical and economic and ecological foundations oflow-carbon development of Ukraine”.

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