Intensive Fertilization Research Articles

Changes in land-leaching nitrogen and its linkages to lake algal blooms in China

Abstract Over the past 50 years, nutrient discharge into freshwater ecosystems has significantly increased due to intensive fertilizer applications in China. This has led to frequent environmental issues associated with nutrient enrichment, such as algal blooms, in a number of individual lakes. However, the link between terrestrial nutrient sources and algal bloom occurrences (BO) at large scales remains under-explored. Here, we simulated long-term changes in nitrogen leaching from terrestrial ecosystems at the national scale from 1979 to 2018, and examined its connection to satellite-derived BO in 56 large lakes across China. Our findings reveal that leached nitrogen exhibited significant increasing trends in 74.5% of the national landmass, with an average increase rate of 0.40 kg N ha-1 yr-2 over the past four decades. Using a 95% quantile regression model, we analyzed the linkage between nitrogen leaching and BO from 2003 to 2018. The results indicated significantly positive correlations in the lakes of the Yangtze Plain during autumn and the lakes of the Northern China and Yunnan-Guizhou Plateau during both summer and autumn. These findings suggest that terrestrial nitrogen discharge critically contributes to algal bloom variations in warmer seasons. Our study provides a comprehensive understanding of escalating nitrogen discharge from terrestrial ecosystems and highlights the potential benefits of fertilization management in mitigating and controlling inland water eutrophication in China.

Three regulatory elements upstream of LMO4 are strongly associated with intermittent fertilization intensity in Chicken.

Intermittent fertilization intensity (IFI) is closely related to higher fertilization in chicken hens. Recent studies have identified genes influencing sperm-oocyte interactions and immune regulation that impact the fertilization process in chickens. This research aims to identify key candidate genes and variants regulating IFI through transcriptomic analysis and dual luciferase assays. Our study's transcriptomic analysis of 12 individuals exhibiting extreme IFI revealed several key candidate genes. Validation using quantitative PCR highlighted PRSS12, DNER, WIF1, and NRXN1 as potential contributors to variations in IFI. Notably, we observed significant differences in the expression of LMO4, located 247.2 kb downstream of IFI-associated genomic regions. To explore variants potentially involved in the regulation of LMO4, we conducted short variant annotation and SV-GWAS, but found no significant associations with IFI. Further motif analysis and dual luciferase validation uncovered three regulatory elements within the associated region that exhibited enhanced promoter or enhancer activity following significant SNP mutations. In conclusion, our findings indicate that LMO4, PRSS12, DNER, WIF1, and NRXN1 serve as primary candidate genes for regulating IFI. Additionally, three regulatory elements significantly associated with IFI were identified upstream of LMO4. These variants hold promise for use in selecting low-IFI lines.

Assessment of N-related microbial processes in the soil of the Polesie National Park and adjacent areas, including reclaimed land.

Soil microorganisms are essential for maintaining ecosystem functionality, particularly through their role in the nitrogen (N) biogeochemical cycle. Thus, they also contribute to greenhouse gas emissions from soils. Microorganisms are sensitive indicators of soil health, as they respond rapidly to disturbances caused by factors like unsustainable agricultural practices or industrial activities, such as mining. These bioindicators are also useful for monitoring the effectiveness of environmental remediation treatments, such as soil reclamation. The study aimed to assess microbial activity related to the N cycle in soils across various habitats (peatland, grassland, forest, and field) under conservation management within the Polesie National Park (PNP), as well as in comparable conventionally managed habitats. Additionally, the effectiveness of soil reclamation was assessed using waste from the mining industry, specifically gangue. Significant differences were observed in the assessed activities, both between habitats and their locations, i.e., within the PNP and outside of it. It was found that microbial activity was lower in soils from the PNP area. This was likely a result of more intensive fertilizer application on soils not subject to the restrictions imposed by park regulations. It should be noted that urease activity, which can contribute to the adverse phenomenon of nitrogen loss from soils when elevated, similarly to nitrous oxide (N2O) emission, was lower in the soils from the park than in those located outside of it. Therefore, designating an area as a national park protects the soil environment from human pressures associated with intensive agriculture, thereby helping to maintain its homeostasis. Reclamation using gangue proved ineffective in restoring microbial activity in degraded soil to the level of cultivated soil outside the park. The assessed activities in the reclaimed soil were lower than the target levels. The results provided valuable information useful for environmental management decisions in terms of soil and air protection, as well as the use of waste for reclamation.

INFLUENCE OF WINTER RAPE FERTILIZATION SYSTEM ON THE CONDITION OF PLANTS BEFORE ENTERING WINTER AND ITS SURVIVAL

The results of a three-year cycle of studying the effect of the combined fertilization system of winter rape on the formation of plant architecture before entering winter and their overall survival during the growing season for two genotypes of medium early and medium ripeness groups are presented. The formation of the basic idiotypic parameters of winter rape plants, which determine the success of their overwintering, namely: diameter of the root collar, height of the growth point above the soil surface, number of formed leaves in the rosette, length of the root system, was investigated and evaluated, and the overall survival of winter rape plants at the final stage of plant maturation (yellow pod) was estimated. The obtained long-term averages were compared with the recommended optimized values of the ratio of certain morphological parameters from the point of view of the factor influence on their formation of the constituent variants of the main and pre-sowing fertilization, the use of growth-regulating drugs and the system of foliar fertilization. The specificity of interaction of fertilizer variants with genotypic response in the context of maturity groups of rapeseed hybrids was evaluated separately. The increase in plant morphometry before their entry into winter and the peculiarities of the gradations of winter rape plant survival in the context of combinatorial experimental variants were evaluated to establish the peculiarities of the gradational comparison of fertilizer intensity both within individual factors of the experiment and in general. Conclusions were drawn regarding the effective possibility of adjusting both the desired morphometry of winter rape plants before their entry into winter and their survival rate during the achievement of physiological maturity by designing an appropriate mineral nutrition system. The achievement of the optimal variant of winter rape plant architecture and their preservation in the variant of combining the technological scheme of fertilization for hybrids of medium early and medium ripeness groups of winter rape, which provides for the following scheme of phenostage operational application BBCH 00, was determined: Diammophoska N-10% P-26% K-26% +1S (144 kg ha-1 for plowing) + Rosafert 15-15-15 (150 kg ha-1 for sowing) + BBCH 19-20 (on frozen ground): UAN-32 (189 l ha-1) + Ammonium Thiosulfate (22 l ha-1) + BBSN 14-16: Regulator Bukat (thiconazole 500 g l-1) (0.5 l ha-1)) + BBCH 35–39: Karamba Turbo 0.65 l ha-1 + Bukat 0.35 l ha-1 + BBCH 31–34: Rosalic (B) (1 l ha-1) + adjuvant Spray-Aid (0.08 l ha-1) + BBCH 51–53: Rosasol 18-18-18 + ME (3 kg ha-1) + adjuvant Spray-Aid (0.08 l ha-1).

Foliar water uptake and phyllosphere microbe colonization increase under higher soil nitrogen availability

Leaf water uptake (FWU) represents an alternative pathway to plant water acquisition that can have positive effects on water and carbon balance. Leaf surface traits including the phyllosphere microbes can affect the leaf wetness capacity and FWU. These functional and structural leaf traits could change depending on soil resources availability. The aim of this study was to evaluate the responses of FWU and leaf surface traits such as contact angle, water drop adhesion (LWA) and phyllosphere-associated microbiota to soil nitrogen addition. Three dominant plant species, Azorella prolifera, Senecio filaginoides, and Papostippa speciosa, of an arid steppe in Patagonia exposed to nitrogen (+N) and nitrogen plus water (+NW) addition for ten years were selected. Leaf contact angle did not exhibit statistical differences among treatments within species. LWA was higher in all treatments with respect to the control (C) for shrub A. prolifera and grass P. speciosa. Nitrogen addition increased significantly FWU in A. prolifera and in P. speciosa with respect to C. Colony-forming units of culturable microorganisms (CFU) on leaf surface responded to N addition, but the changes were statistically significant in S. filaginoides and P. speciosa in +NW, increasing three and eight times, respectively, in relation to the C. A positive linear relationship was found between FWU and LWA across species and treatments. On the other hand, CFU of phyllosphere was negative and exponentially correlated with LWA and FWU, across species and treatments. The results suggest that soil N enrichment could affect functional leaf traits and phyllosphere microbiota in a way that may confer a higher potential to cope with drought by facilitating the use of alternative water sources. On the other hand, we suggested that species with leaves more colonized have less surface exposed for FWU and could have lower wettability depending on the hydrophobicity degree of microbes. However, a higher cover of epiphyte’s microorganisms could compensate the effects of lower FWU by avoiding the leaf dehydration. This study contributes to a better understanding of plant leaf-microbe interactions under higher N atmospheric deposition and intensive fertilization as global agricultural production is expected to increase.

Calculating the effect of intensive use of urban organic waste on soil concentrations of potentially toxic elements in a peri-urban agriculture context in Norway

BackgroundRecycling nutrients and organic matter available as waste in urban areas may close nutrient gaps and improve soil quality, but the concentrations of potentially toxic elements (PTEs) are commonly higher than in mineral fertilisers. How quickly may the limits for soil quality be exceeded, and for which elements, if such materials are applied intensively? For a rough answer to this question, we used soil data from ten case farms near Oslo and Bergen (Norway) to estimate how PTE concentrations increased when the demand for nitrogen (N), phosphorus (P) and potassium (K) in a theoretical carrot crop produced every year was covered by compost or digestate from source-separated food waste, or composted garden waste, compared with manure from horses and poultry which are often kept in peri-urban areas.ResultsWith the intensive fertilisation assumed here, the Norwegian soil quality limits for PTEs were reached within 20–85 years, and faster for soil with more organic matter since regulatory limits set by weight discriminate soils with low bulk density. The limits were reached first for Cu and Zn, which are both essential micronutrients for crop plants. The concentrations of macronutrients in the urban waste-based fertilisers were not well balanced. Rates covering the K demand would lead to high surpluses of P and N. In peri-urban vegetable growing, high applications of compost are not unusual, but more balanced fertilisation is required.ConclusionsThe Norwegian regulations for PTEs in organic soil amendments and agricultural soil are stricter than in the EU, and do not support recycling of organic matter and nutrients from urban waste. Many materials which can only be applied with restricted amounts to Norwegian agricultural soil, may be applied according to crop demand in the EU. Growers utilising urban waste-based fertilisers intensively should monitor the soil regularly, including PTE analyses. Soil sampling should occur on fixed sampling points to reveal changes in concentrations over time. Norwegian authorities should consider a revision of the organic fertiliser regulation to support recycling of valuable organic materials. There is a need for more data on the PTE concentrations in agricultural soil and organic fertiliser materials.

Plant functional structure varies across different management regimes in submontane meadows

Seminatural grasslands are among the most biodiverse habitats in Europe, and they have great conservation value. However, in recent decades, they have been threatened by either intensive fertilization or afforestation or, conversely, by abandonment due to changes in agricultural practices. The impact of management, its frequency or intensity on seminatural grassland communities is traditionally evaluated through views on the composition of communities and their diversity. A better understanding of the functioning of plants in managed grassland ecosystems could be achieved by considering plant functional traits (PFTs). In this study, we investigated whether sites with different management practices differ from each other in terms of the representation of the main PFTs. We studied a permanent plot series of 30 grassland sites in central Slovakia that had been managed or abandoned for over 10 years. Individual management consisted of low-intensity mowing (MGM), medium-intensity grazing (MGP), and abandonment (MGA). Hemicryptophytes, perennials, and semi-rosette species were dominant under all management regimes. We found significant differences in the coverage of the studied PFTs among the sites managed by phytomass removal (mowing, grazing) and abandoned sites. Compared with the MGA sites, mowed and grazed sites were characterised by high proportional coverages of species with medium plant heights (0.3–0.6 m), rosette species, and graminoids. The MGA sites presented high coverages of species with high plant heights (> 0.6 m), competitors, phanerophytes, forbs, geophytes, species with vegetative and seed reproduction types, species with long flowering periods (3 months or more), and species with summer green leaves. The MGM sites supported species with large seeds (seed mass > 2 mg), reproduction type by seed (seeds), and species with short flowering times (1–2 months), whereas the MGP sites supported species with small plant heights (plant height < 0.3 m) and species with persistent green leaves. The communities of submontane Carpathian meadows with different types of management differ in terms of the representation of selected plant functional traits, especially between managed and abandoned sites. This approach is useful not only for understanding the mechanisms involved in the application of different management methods but also for predicting changes in the responses of the functional properties of plants when abandoning grassland habitats.

Underappreciated roles of soil nitrogen oxide emissions on global acute health burden

The recognized importance of ambient fine particulate matter (PM2.5), ozone (O3), and nitrogen dioxide (NO2) on human health has prompted the world to enact increasingly strict regulations on anthropogenic nitrogen oxides (NOx) emissions. However, the health concerns from soil NOx, potentially driven by fertilizer input but conventionally categorized as natural sources, remain less studied. Here, we emphasize the underappreciated roles of soil NOx emissions on health burden attributable to short-term PM2.5, O3, and NO2 exposure. Globally, we quantify acute health effects using machine-learning-based daily exposure estimates and identify influences of soil NOx emissions based on chemical transport model simulations. We find that 72.3% of the globe is affected by soil NOx emissions, whose contributions to short-term PM2.5, O3, and NO2 pollution lead to 13.9 (95% Confidence Interval [CI]: 9.1–18.8), 26.0 (18.2–34.2), and 13.9 (10.3–17.5) thousand premature mortality, respectively, in 2019. With distinct variations in regions, seasons, and pollutants, soil NOx-originated air pollution poses a global health concern, particularly for developing regions and intensively agricultural areas. In response to the intensive fertilizer use, South Asia, Southern Sub-Saharan Africa, and Central Europe witness the largest soil NOx-related health burden of up to 1.6 (95% CI: 1.1–2.1) mortality per 100k population. The overall health risk peaks in May, with O3 pollution typically dominating the soil NOx-attributable health burden during warm seasons and NO2 or PM2.5 during cold months. Our study highlights the necessity of dynamically adapted agricultural strategies for health-oriented multi-pollutant control, among which the improved use of synthetic fertilizers deserves priority under the ever-changing climate.

The heterogeneous response in leaf traits among seasons and plant types of an evergreen broadleaf forest in western China to nitrogen addition was regulated by fertilization intensity

The heterogeneous response in leaf traits among seasons and plant types of an evergreen broadleaf forest in western China to nitrogen addition was regulated by fertilization intensity

Vester Hedegaard. A Late Neolithic Settlement with House Remains, Offering Pits, Carbonised Grain and Animal Bones in Northern Jutland

Abstract A settlement with six houses and two offering pits is presented in the article. The settlement is roughly dated to the Late Neolithic II (c.1950–1700 BCE). It contained comprehensive subsistence material, including carbonised grain, food crust and burned bones of a cow and a smaller mammal. The two animals were possibly trapped in a house fire and interpreted as evidence of livestock stalling during the Late Neolithic. The material forms the basis of an interpretation of the subsistence, which is suggested to have consisted of cereal cultivation enhanced by intensive fertilisation with dung from domestic animals. This cultivation cycle ensured stable food production on the lean soils of the area during the occupation. Analysis of the food crust indicates that fruit wine was also consumed in the settlement.

Performance of different wheat varieties and their associated microbiome under contrasting tillage and fertilization intensities: Insights from a Swiss long-term field experiment

Winter wheat is an important global cereal crop. However, conventional farming practices, characterised by intensive tillage and high fertilizer inputs, pose significant threats to the environment. In response, more conservative management practices are being applied aiming to maintain wheat production while promoting a beneficial microbiome. Here, we evaluated the suitability of three different wheat varieties for less intensive agricultural systems, focusing on reduced tillage and fertilizer intensity. The study was conducted over two consecutive years in a Swiss long-term field experiment comparing conventional versus reduced tillage and full fertilization versus half fertilization. In addition, we investigated the composition of plant-associated microbial communities using amplicon sequencing of phylogenetic marker genes, specifically targeting bacteria and fungi in rhizosphere samples and fungi in root samples. Our results revealed that in our study wheat variety most strongly predicted grain yield and quality, independent of tillage and fertilization intensity. Specifically, wheat varieties demonstrated higher yields and N uptake in plots subjected to conventional ploughing and full fertilization compared to those under reduced tillage and half fertilization. We found no significant effect of wheat variety on the composition of microbial communities. However, tillage emerged as the primary factor influencing microbial community composition in the rhizosphere, while fertilization intensity significantly impacted fungal communities in the root system. These findings underscore the complex interplay between agronomic practices, plant genetics, and microbial dynamics in agroecosystems, emphasizing the need for holistic and adaptive approaches and their further development to ensure sustainable crop production.

Shallow drainage of agricultural peatlands without land-use change: have your peat and eat it too

IntroductionDrainage for agricultural purposes is one of the main drivers of peatland degradation, leading to significant greenhouse gas (GHG) emissions, biodiversity loss, and soil eutrophication. Rewetting is a potential solution to restore peatlands, but it generally requires a land-use shift to paludiculture or nature areas.MethodsThis study explored whether three different water level management techniques (subsoil irrigation, furrow irrigation, and dynamic ditch water level regulation) could be implemented on dairy grasslands to yield increases in essential ecosystem services (vegetation diversity and soil biogeochemistry) without the need to change the current land use or intensity. We investigated vegetation diversity, soil biogeochemistry, and CO2 emission reduction in fourteen agricultural livestock pastures on drained peat soils in Friesland (Netherlands).ResultsAcross all pastures, Shannon-Wiener diversity was below 1, and the species richness was below 5. The plant-available phosphorus (P) was consistently higher than 3 mmol L−1. None of the water level management (WLM) techniques enhanced vegetation diversity or changed soil biogeochemistry despite a notable increase in water table levels. The potential for CO2 emission reduction remained small or even absent. Indicators of land-use intensity (i.e., grass harvest and fertilization intensity), however, showed a strong negative correlation with vegetation diversity. Furthermore, all sites’ total and plant-available P and nitrate exceeded the upper threshold for species-rich grassland communities.DiscussionIn conclusion, our research suggests that incomplete rewetting (i.e., higher water tables while maintaining drainage) while continuing the current land use does neither effectively mitigate GHG emissions nor benefit vegetation diversity. Therefore, we conclude that combining WLM and reducing land-use intensity is essential to limit the degradation of peat soils and restore more biodiverse vegetation.

Research on the Impact of Agricultural Production Outsourcing on Farmers’ Fertilizer Application Intensity: An Inverse U-Shaped Relationship

Agricultural production outsourcing services encourage a shift in the way crops are grown in developing countries and make it easier for small farmers to join the social division of labor in agriculture. This makes production more efficient and has a big effect on the inputs used in agriculture, especially fertilizer. This paper empirically tests the impact of production outsourcing on farmers’ fertilizer intensity using the instrumental variables method with non-planar panel data from the 2020–2022 China Land Economy Survey (CLES) of farm plots. The results showed that there was a significant inverted U-shaped relationship between the degree of agricultural production outsourcing and the intensity of fertilization on farmers’ plots. Mechanistic analysis shows that agricultural production outsourcing affects the fertilizer intensity by changing the labor allocation of farmers. Especially as the degree of agricultural production outsourcing increases, the intensity of farm labor inputs by farmers gradually decreases, and the impact of fertilizer intensity on the plots showed a tendency to be promoted first and then suppressed. The moderating effect showed that plot size was a major moderating factor. This means that the bigger the plot, the flatter the inverted U-shaped curve became, and the same level of outsourcing could lead to less fertilizer application. This happened by moving the inflection point of the inverted U-shaped curve to the left, which stopped the fertilizer application at a lower level of outsourcing. Heterogeneity analysis showed that participation in technology-intensive production outsourcing was beneficial in terms of reducing fertilizer intensity, and that an increased degree of agriculture production outsourcing was beneficial for farmers with large plot sizes and younger heads of household.

Genome-wide re-sequencing reveals regulatory genes and variants involved in the regulation of intermittent fertilization intensity in Wenchang chickens.

Intermittent fertilization intensity (IFI) is closely related to higher fertilization in chickens, but the genetic basis of IFI is not clearly understood. Here, we sampled a total of 939 Wenchang chickens with IFI. The IFI traits had negative correlation with the fertilization rate and exhibited huge phenotypic variations among individuals of the same strain. Based on SNPs derived from a subset of 499 whole genome data, a genome-wide association study with mixed linear model and further linkage disequilibrium analysis were performed to test potential associations between IFI traits and genomic variants. We identified 35 SNP variants and a 19.82 kb linkage disequilibrium block on chr8 significantly associated with IFI. This block is in the intron of LOC101750715, which shows significant homology with the human LMO4. Therefore, LOC101750715 and LMO4 may regulate IFI. The oviduct's immune regulation is crucial for fertilization. LMO4, activated by IL-6 and IL-23, promotes inflammation in epithelial cells. Thus, LOC101750715 and LMO4 may affect fertilization by regulating oviductal inflammation, impacting IFI. Our findings will provide targets for molecular-marker selection and genetic manipulation for lines of chickens with lower IFI.

Annual emissions of N2O, NO, HONO, and NH3 from maize-wheat fields in the North China Plain

Fertilized agricultural soil is a significant source of gaseous nitrogen compounds (GNCs), including N2O, NO, HONO, and NH3. The North China Plain (NCP) is the “hot region” for the release of these GNCs due to intensive fertilization practices. However, existing research has primarily focused on N2O emissions from fertilized farmland in the NCP, lacking comprehensive observational studies on other GNCs. Therefore, a continuous cumulative sampling technique (open-top dynamic chamber system) was utilized in this study to simultaneously measure the exchange fluxes of N2O, NO, HONO, and NH3 over summer maize-winter wheat rotation fields in the NCP. Results showed that GNC emissions from the soil displayed distinct diurnal variations, with higher emissions during the day attributed to elevated soil temperature. However, N2O emissions remained consistent between day and night, potentially influenced not only by soil temperature but also by soil humidity. Annual cumulative emissions and emission factors (EFs) for four GNCs were determined, indicating that N2O, NO, and NH3 emissions during the maize season were 1.38–2.37 times higher than those during the wheat season, with 98 % of HONO emissions occurring in the maize season. Additionally, the study first presented the annual HONO EFs of 0.36 ± 0.03 % in fertilized farmland. Furthermore, a comparison revealed that the fluxes of N2O, NO, NH3, and HONO using the conventional single-point sampling method were 26.4 %, 13.9 %, and 8.10 % lower, and 7.86 % higher compared to the continuous cumulative sampling method recommended in this study. In general, this study provided precise measurements of GNC emissions from farmland, offering essential foundational data for modeling parameters and contributing to the formulation of regional air pollution prevention and control policies.

Dynamics of a size-structured predator–prey model with chemotaxis mechanism

This paper is concerned with a size-structured diffusive predator–prey model with chemotaxis mechanism. The existence, linearized stability and monotonicity with respect to the growth rates of boundary steady-state solutions are analyzed. Moreover, the global stability of trivial steady-state solution under certain conditions is proved by constructing Lyapunov functional. We investigate the local and global bifurcations of positive steady-state solutions that emanate from semi-trivial steady-state solutions using Lyapunov–Schmidt reduction and bifurcation techniques when the fertility intensity of a predator or prey is used as a bifurcation parameter. It is shown that the nonlinear nonlocal chemotaxis term can lead to the emergence of Allee effect.

SUBSTITUSI SEBAGIAN PUPUK ANORGANIK DENGAN PUPUK HAYATI TERHADAP PRODUKSI BAWANG MERAH

Shallots are an important crop with high economic value in Indonesia. Shallot production usually depends on intensive fertilization. Inorganic fertilizers were increasingly rare and more expensive at the market level. Inorganic fertilizers were scarce in society and their prices were more expensive at the market level. Biofertilizers made from superior microbial active ingredients have long been used to substitute inorganic fertilizers, but the right combination dose has not been found to increase the yields. The research aimed to study the level of effectiveness of biological fertilizers in substituting inorganic fertilizers and getting the right dose to increase shallot production. The research was conducted from February to April 2019 in the Research Plantation of PT. Indo Acidatama Tbk, Karanganyar, Central Java. Four treatments were tested on shallot seeds under a completely randomized design non-factorial: (P1) NPK 1200 kg/ha, (P2) NPK 900 kg/ha + biofertilizer 10 l/ha, (P3) NPK 600 kg/ha + biofertilizer 20 l/ha, dan (P4) NPK 300 kg/ha + biofertilizer 30 l/ha. The results showed that 20 l/ha of biofertilizers combined with a dose of 600 kg/ha of inorganic fertilizer effectively increases shallot production to reach 6.78 tonnes/ha. Biofertilizers could substitute several inorganic fertilizers so that are indicated by optimally wet biomass weight, weight of bulbs, number of bulbs, and diameter of bulbs.

VITALITY OF WINTER RAPE AGROCENOSIS UNDER DIFFERENT FERTILIZATION OPTIONS IN THE CONDITIONS OF THE RIGHT-BANK FOREST-STEPPE OF UKRAINE

The results of a two-year cycle of studying the vitality structure of the agrophytocenosis of winter rape intensive high-yielding hybrid Absolute under different fertilization systems, which provided different options in terms of background mineral nutrition, the use of growth-regulating drugs and different options for foliar feeding, are presented. The morphological parameters of winter rape plants were studied with the formation of four main blocks of indicators (root, stem, assimilation surface, generative part) and the initial data set was formed, which allowed to determine such indicators of agrocenosis vitality as the vitality coefficient, the module of morphological variability, the modified index of morphological integration, the quality index, the index of agrophytocenosis prosperity, the index of dimensional plasticity. The analysis of the determined parameters of vitality in statistical integration with the calculation of the range and mean value, variation and share of each factor according to the experimental scheme in the context of a multivariate analysis of variance scheme allowed to identify the factor components of influence on the vitality of winter rape agrocenosis, taking into account the variant of background fertilization, the use of growth regulation and foliar fertilization system in order to find the optimal variant of combined fertilization of winter rape. The increase in the optimization of winter rape vital structure in comparison with the control variant was estimated, with an additional increase in the indicators for a single graded increase in fertilization intensity. Conclusions were made about the optimal morphostructure of winter rape agrocenosis in variants of maximum intensification of mineral fertilizers application. At the same time, the maximum indicators of vitality assessment of winter rape agrocenosis in the variant of combining complex background fertilization with the use of various forms of fertilizers in combination with sulfur application against the background of growth-regulating drugs and complex application of multiple foliar fertilization were established, which provided the following parameters of plant vitality tactics: vitality coefficient (IVC) 1,312, module of morphological variability (Modx) 0.98–1.00, modified index of morphological integration (Immi) 0,711–1,335, quality index (Q) 43.00, index of agrophytocenosis prosperity (IQ) 3,07, index of dimensional plasticity (ISP) 1,427.

Regional features of the manifestation of demographic threats in terms of characteristics of marriage, motherhood and childhood

The subject of the research is the regional characteristics of demographic indicators of marriage, motherhood and childhood, their relationship with the indicator of natural growth. At the same time, the natural decline of the population is considered as one of the key threats to the demographic and, consequently, national security of the population of the Russian Federation, since it entails a number of economic and geopolitical risks. The variability of indicators of marriage, motherhood and childhood is considered in the study as a possible source of variability in natural growth. Therefore, the regional peculiarities of the numerical characteristics of each of these features are analyzed in detail. Special attention is paid to regions showing abnormal values. In addition, the nature of the influence of individual indicators of marriage, motherhood and childhood on the natural growth rate has been studied in order to identify key factors determining the variability of the latter. The paper uses methods of exploratory data analysis: elements of descriptive statistics and diagrams to demonstrate trends . The closeness of the relationship between the indicators of the natural growth coefficient and the indicators of marriage, motherhood and childhood is also determined and a model of linear regression of the natural growth coefficient on the total fertility rate is constructed. The authors' contribution to the development of the topic is that, despite the simplicity of the stated methods, the study allowed us to identify regions with specific features in one or more indicators of marriage, motherhood, childhood, as well as natural growth. Further study of the features of regional demographic policy, the state of health, and cultural characteristics of the selected regions will allow us to borrow positive experience and correct negative trends, which should lead to a decrease in the factors determining the depopulation of the Russian population in terms of marriage, motherhood and childhood. The regression model allowed us to conclude that measures are needed to increase the total fertility rate, since, among the factors considered, the natural growth rate turned out to be the most sensitive to this trait, which simultaneously characterizes the propensity of women to motherhood and the intensity of fertility

Light Intensity: A Key Ecological Factor in Determining the Growth of Pseudolarix amabilis Seedlings

The notable absence of juvenile Pseudolarix amabilis trees in forest understories suggests their vulnerability to ecological niche competition, leading to limited survival prospects. This study examines the key factors limiting the growth of P. amabilis seedlings by investigating the effects of five ecological factors: light intensity, rainfall, groundwater level, soil type, and type of fertilization, on the growth of one-year-old P. amabilis seedlings. Our results demonstrate that increasing the light intensity promotes plant growth by augmenting the leaf count, leaf biomass, plant height, stem biomass, root biomass, and total biomass. Further analysis reveals that increased light intensity influences biomass allocation, reducing the specific leaf area and leaf–stem biomass ratio, and favoring root and stem growth over leaf investment. Rainfall, groundwater level, fertilization type, and rhizosphere soil type primarily influence root growth by impacting the soil’s physicochemical properties. Specifically, rising groundwater levels lower the soil temperature and increase the soil moisture, total potassium content, and soil pH, leading to reductions in root biomass, plant height, net height increment, leaf number, and total biomass. When groundwater levels reach 21 cm and 28 cm, submerging the surface soil layer, root biomass decreases by 1.6 g/plant (−51.6%) and 2.3 g/plant (−74.2%), respectively. Further analysis reveals a gradual decrease in the root–shoot ratio above the 14 cm groundwater level, while the specific leaf area and leaf–stem biomass ratio remains unaffected, indicating stronger belowground root stress compared to aboveground stem and leaf components. The results highlight light intensity as the key ecological factor determining the growth of P. amabilis seedlings. These findings underscore the importance of considering light intensity in the management of natural stands, the cultivation of artificial forests, and the nursery cultivation of endangered P. amabilis.