Using Brown Algae in the Plant–Soil System: A Sustainable Approach to Improving the Yield and Quality of Agricultural Crops

Excessive consumption of chemical fertilizerchemical fertilizer for improving the yield and health of agricultural cropsagricultural crops eliminates the ecosystemecosystem balance in the water and soil environment. For the environmental concerns and high cost of chemical fertilizer, the production of biological fertilizersfertilizers has been considered. In sustainable agricultural systems, microbial inoculantsmicrobial inoculants have special importance in increasing productivity and sustainable soil fertility management. The use of microbial inoculants leads to stability of soil resources, maintains long-term production capacity, and prevents environmental pollution. Decades of research in greenhouse and field conditions have shown that these inoculants are more effective on plants’ growth when used as a consortium. In addition to the individual effects of microorganisms, productivity and quality of agricultural crops can be improved by inoculation with other microorganisms due to their synergistic effects. The association of different organisms in microbial consortiummicrobial consortium enhances fertility and health status of soil for the growth of legume and non-legumenon-legume plants. This chapter presents an overview of recent researches on the soil microbial consortiamicrobial consortia, mechanisms, and their impact on improving the productivity and quality of agricultural crops.

Modern agricultural production is faced with the need to increase the yield and quality of agricultural crops. For sugar beet, the key factors determining the yield and quality of root crops are the content of alpha-amine nitrogen and the alkalinity of sugar beet roots. These parameters have a significant impact on plant metabolism, growth and development, which affects the productivity and quality of the crop. The goal of the research is to analyze the concentration of alkalinity and the content of alpha-amine nitrogen in sugar beet roots. The objective is to determine the content and effect of alpha-amine nitrogen and alkalinity on sugar beet roots. The Research methods. The studies were conducted in the field and laboratory conditions. Detailed experimental schemes were developed. Statistical analysis of the results was performed as part of the study. The Results. The comprehensive analysis included an assessment of alkalinity and alpha-amine nitrogen content in sugar beet roots. In 2023, the alkalinity index varied in the range of 1.31-3.59 mg-eq/100 g. In 2024, there was a slight increase in alkalinity to 1.54-3.73 mg-eq/100 g. High content of alpha-amine nitrogen negatively affects the process of sugar formation in sugar beet roots, so this indicator requires special attention and study in parental forms and F1 hybrids of sugar beet. In the course of the analysis, a relationship between the alkalinity level and the content of alpha-amine nitrogen, which determines their impact on sugar beet roots has been established. Conclusion. The quality indicators of sugar beet roots deteriorate due to an increase in the concentration of alkalis and alphaamine nitrogen, which is most clearly seen in dry years. According to the results of statistical processing, the greatest impact (20.5%) on the alkalinity indicator was achieved with the combined action of three components (Year x Genotype x Background), and alpha-amine nitrogen was affected by a combination of factors - Year x Genotype and amounted to 27.8%

Yield and quality of agricultural crops are influenced by a large number of factors. Some of these are inherent to the field on which the crop is grown. They define the intrinsic capacity of a field and cannot or hardly be modified by man. The so-called management factors can be adjusted or influenced as required for optimum production. In the present concept, the maximum attainable yield is considered to be the highest observed yield within a group of fields with comparable intrinsic value, further called iso-group. The grouping (positioning step) is based on a set of permanent characteristics determined mainly by the physical environment. Each unique combination of these characteristics, established by using a GIS-tool, gives rise to a new iso-group. After appointing each field to an iso-group, a ranking can be made within each group based on yield or quality. During the diagnosis step the contribution of each management variable to the observed variation in yield and/or quality within an iso-group, is determined. In this way the most relevant variables are selected and the relationship with yield and/or quality is established. Based on these relationships specific measures can be suggested to improve the yield and/or quality of the crop on a specific field (advising step). By applying these recommendations the farmer is expected to obtain yields that approximate the maximum intrinsic capacity of his plot.

Impact of micronutrients in mitigation of abiotic stresses in soils and plants—A progressive step toward crop security and nutritional quality

Over the past 25 years, the influence of siliceous rocks (diatomite, zeolite, flask) on soil properties (typical chernozem, leached chernozem), yield and quality of agricultural crops (cereals, potatoes and vegetables, technical) when used both in pure form and together with mineral fertilizers and bird droppings has been studied. The possibility of creating new types of more effective fertilizers based on siliceous rocks by enriching them with elements or compounds (in particular amino acids) that most fully meet the requirements of crops has been studied. Studies have shown that the yield of grain crops when using diatomite as a fertilizer is little inferior to mineral fertilizers. Thus, the increase in grain yield of winter wheat on average over all the years of research reached 0.60–1.30, spring wheat – 0.15–0.67, barley – 0.50–0.93 t/ha. The increase in corn grain yield, depending on the dose of zeolite application, ranged from 0.93 (dose of 500 kg/ha) to 1.36 (dose of 2000 kg/ha) t/ha. Potatoes and vegetables (cucumbers, tomatoes, carrots, table beets), as well as industrial crops (sugar beet, sunflower) are highly responsive to the use of siliceous products as fertilizers. In particular, the yield of sugar beet root crops increased by 6.5 t/ha on average when diatomite was applied at a dose of 3 t/ha, and in some years – up to 8.6 t/ha. The increase in crop yield increased very significantly when combined with nitrogen fertilizers from N30 to N60 – by 11.3 and 12.5 t/ha. The high efficiency of silicon-containing rocks as fertilizers of agricultural crops is due to their complex influence on the fundamental properties of the soil: physical (structural condition, soil density, structure of the arable layer), biological (activity of soil microorganisms), chemical (nutritional regime, environmental safety), as well as on the protective properties of plants.

The article scientifically substantiates the literary sources on the cultivation of winter triticale for grain and green fodder. It is proved that the use of new high-yielding varieties of winter triticale is a powerful factor in stabilizing the grain economy of the country. Therefore, in this context, it is important to use the latest measures in innovative technologies to increase the yield and quality of crop production. Among the innovative measures in the technological process of growing agricultural crops, foliar feeding of plants with microfertilizers of biological, organic and chemical origin has become widely popular. With the correct application of these preparations, foliar feeding can be a more effective tool for eliminating the deficit in micro- and macroelements, compared to the application of mineral fertilizers in the soil, since nutrients directly enter the plant tissue in critical stages of development. Foliar fertilization does not replace soil application of fertilizers, but contributes to the effective addition of the main nutrition system and ensures an increase in the yield and quality of agricultural crops. It has been established that winter triticale is a promising, high- yielding crop, regardless of its direction of use (grain, green mass). By biological characteristics, the growth rates of the stem of winter triticale are determined by the genetic trait characteristic of all cereal crops. It has been established that from the tillering stage to the full exit into the tube, that is, during this interphase period, the height of the plants increased by 2.2-2.3 times, regardless of the varietal characteristics of the culture. It has been previously found that the use of Dr Green preparations for foliar feeding during the main growth and development phases is aimed at suppressing growth processes in height, starting from the full exit into the tube.

The goal is to develop the main elements of biologization of the No-till system in the conditions of the Piedmont-steppe zone of Crimea, to study the effect of various types of ground cover crops on soil fertility, yield and grain quality of agricultural crops in conditions of insufficient and unstable moisture. When intermediate crops were cultivated as ground cover crops in the No-till system, the available moisture reserves in the meter layer were at a satisfactory level after vetch cultivation - 107.6 mm and in the control (without ground cover crops) - 99.6 mm. The highest yield of green mass of ground cover crops was in all variants with the use of multicomponent mixtures, which was 2 or more times higher than the yield of intermediate ground cover crops from 1–2 and 3 spring crops and almost 10 times higher than that of winter rye. This made it possible to fix 30–33 kg of nitrogen, 4–5.9 kg of phosphorus and 13.9–16.7 kg of potassium in plants and in the root system annually by the end of the growing season of spring crops per hectare of sowing.

The growing global population is driving up demand for agricultural goods at a never-before-seen rate. Improving crop yield and quality is essential to meeting this growing demand. The yield and quality of agricultural crops may be greatly increased by using agronomic techniques. Although it is known that changing climate circumstances have a detrimental impact on crop development, yield, soil quality, and ultimately the nutritional content of agricultural food, such agronomic methods under changing climate conditions are insufficient to boost crop productivity. In order to increase the production potential of agricultural crops, several agronomic improvements have been made in the previous few decades. These include the application of resource conservation technology and conservation agricultural methods. Therefore, it is essential to adopt various adaptive agricultural practices that are specifically resource-conserving, such as crop diversification, mulching, crop rotation, agroforestry, intercropping, and the push-pull system of crop pest and disease management, etc. in order to effectively deal with such unfavourable situations. These agronomic approaches, which are being advocated to increase agricultural production and profitability, are described in the review along with their methods for enhancing crop performance and quality.

Sargassum is exploited as a biostimulant in agriculture for its rich bioactive compounds. Extracts from Sargassum promote plant growth, nutrient uptake, and stress tolerance in agricultural and horticultural crops. Sargassum is a most abundant seaweed, and it occupies a huge proportion of coastal plants. This review unveils key active constituents present in Sargassum such as proximate and ultimate compounds, antioxidants, phytohormones, glucosinoids, bioactive compounds, and enzymes. As a biostimulant, Sargassum mitigates biotic and abiotic stresses. It has a positive impact on soil health, plant physiology, crop yield, animal antimicrobials, and animal feeding, as well as highlighting some sustainable agricultural practices discussed in the review. Integrating Sargassum-based biostimulants in agriculture holds promise for resilient and productive crops with minimal environmental impact. These characteristics are considered the future of ideal agrochemical properties in all dimensions of plant growth and development. These kinds of organic-based biostimulants will be ideal alternatives to toxic chemical agents.

ABSTRACTEarlier, we demonstrated that transcript levels of METAL TOLERANCE PROTEIN2 (MTP2) and of HEAVY METAL ATPase2 (HMA2) increase strongly in roots of Arabidopsis upon prolonged zinc (Zn) deficiency and respond to shoot physiological Zn status, and not to the local Zn status in roots. This provided evidence for shoot-to-root communication in the acclimation of plants to Zn deficiency. Zn-deficient soils limit both the yield and quality of agricultural crops and can result in clinically relevant nutritional Zn deficiency in human populations. Implementing Zn deficiency during cultivation of the model plant Arabidopsis thaliana on agar-solidified media is difficult because trace element contaminations are present in almost all commercially available agars. Here, we demonstrate root morphological acclimations to Zn deficiency on agar-solidified medium following the effective removal of contaminants. These advancements allow reproducible phenotyping toward understanding fundamental plant responses to deficiencies of Zn and other essential trace elements.

Plant growth-promoting bacteria (PGPB) are beneficial free-living soil, rhizospheric, epiphytic, and endophytic microorganisms capable to stimulate plant growth and increase host plant resistance and tolerance to a wide range of biotic and abiotic stresses. A number of PGPB associated with wheat and different cereals have been identified comprising bacterial strains belonging to such genera as Bacillus, Azospirillum, Arthrobacter, Acinetobacter, Azotobacter, Citricoccus, Lysinibacillus, Burkholderia, Paenibacillus, Serratia, Pseudomonas, etc. Several studies have confirmed that some species of bacteria associated with the rhizosphere of plants are useful for growth, development, and formation of yield and quality of agricultural crops. Furthermore, those bacteria which are capable to colonize internal plant tissues, namely, endophytes, may be more successful (compared to rhizospheric bacteria) in the promotion of plant growth and development under both normal and long-term stress conditions. PGPB-induced development of defense responses and the formation of tolerance under the exposure to various abiotic stresses have been demonstrated in numerous plants, including wheat. The mechanisms of such physiological effect of PGPB on host plants are believed to be varied, intertwined, and specific; PGPB positively affects on plants through biosynthesis of numerous biologically active compounds, for instance, substances with antibiotic and insecticidal activities, biosurfactants, siderophores, chelators, phytohormones, enzymes, and nitrogen fixation, regulating the level of ethylene in plants, and improving macro−/micronutrient bioavailability, development of systemic resistance to diseases, and tolerance to abiotic stresses with involving salicylate-dependent or jasmonate-dependent signaling pathways. In this review, the role of beneficial PGPB in ameliorating the many deleterious consequences during abiotic stresses has been considered. Besides, B. subtilis’ efficiency on abiotic stress tolerance induction in wheat according to their ecological groups (ecotypes) is discussed as well.

Tropospheric ozone causes various negative effects on plants and affects the yield and quality of agricultural crops. Here, we report a genome-wide association study (GWAS) in rice (Oryza sativa L.) to determine candidate loci associated with ozone tolerance. A diversity panel consisting of 328 accessions representing all subgroups of O. sativa was exposed to ozone stress at 60 nl l(-1) for 7h every day throughout the growth season, or to control conditions. Averaged over all genotypes, ozone significantly affected biomass-related traits (plant height -1.0%, shoot dry weight -15.9%, tiller number -8.3%, grain weight -9.3%, total panicle weight -19.7%, single panicle weight -5.5%) and biochemical/physiological traits (symptom formation, SPAD value -4.4%, foliar lignin content +3.4%). A wide range of genotypic variance in response to ozone stress were observed in all phenotypes. Association mapping based on more than 30 000 single-nucleotide polymorphism (SNP) markers yielded 16 significant markers throughout the genome by applying a significance threshold of P<0.0001. Furthermore, by determining linkage disequilibrium blocks associated with significant SNPs, we gained a total of 195 candidate genes for these traits. The following sequence analysis revealed a number of novel polymorphisms in two candidate genes for the formation of visible leaf symptoms, a RING and an EREBP gene, both of which are involved in cell death and stress defence reactions. This study demonstrated substantial natural variation of responses to ozone in rice and the possibility of using GWAS in elucidating the genetic factors underlying ozone tolerance.

Salt stress greatly affects the yield and quality of agricultural crops, limiting their geographic distribution. Valine-glutamine (VQ) motif-containing proteins function as transcriptional regulators of plant growth and stress responses. However, the role and underlying molecular mechanisms of VQ proteins in apple (Malus domestica) salt stress responses remain largely unknown. Here, MdVQ17 was identified as a salt-responsive gene that negatively regulates salt tolerance in apple plants by increasing the Na+/K+ ratio and suppressing reactive oxygen species (ROS) scavenging under salt stress. MdWRKY100, a WRKY transcription factor that enhances apple salt tolerance, was identified as an MdVQ17-interacting protein. MdWRKY100 directly bound to the Arabidopsis K⁺ TRANSPORTER 1-LIKe (MdAKT1-like) and PEROXIDASE 57 (MdPER57) promoters, activating their transcription. MdVQ17 inhibited the binding and transcriptional activation activity of MdWRKY100 at these promoters, thereby suppressing MdWRKY100-mediated regulation of Na+/K+ homeostasis and antioxidant enzyme activity. MdVQ37, another MdWRKY100-interacting VQ protein, modulated the MdWRKY100-mediated salt response through a similar mechanism. Overall, these findings reveal that the MdVQ17/MdVQ37-MdWRKY100 module co-regulates Na+/K+ homeostasis and ROS scavenging by modulating MdAKT1-like and MdPER57 expression, providing insights into how the VQ-WRKY complex influences salt tolerance in apple.

The use of irrigation water containing cyanobacterial toxins may generate a negative impact in both yield and quality of agricultural crops causing significant economic losses. We evaluated the effects of microcystins (MC) on the growth, nodulation process and nitrogen uptake of a Faba bean cultivar (Vicia faba L., Fabaceae), particularly the effect of MC on rhizobia-V. faba symbiosis. Three rhizobial strains (RhOF4, RhOF6 and RhOF21), isolated from nodules of local V. faba were tested. The exposure of rhizobia to MC showed that the toxins had a negative effect on the rhizobial growth especially at the highest concentrations of 50 and 100 μg/l. The germination of faba bean seeds was also affected by cyanotoxins. We registered germination rates of 75 and 68.75% at the toxin levels of 50 and 100 μg/l as compared to the control (100%). The obtained results also showed there was a negative effect of MC on plants shoot, root (dry weight) and total number of nodules per plant. Cyanotoxins exposure induced a significant effect on nitrogen assimilation by faba bean seedlings inoculated with selected rhizobial strains RhOF6 and RhOF21, while the effect was not significant on beans seedling inoculated with RhOF4. This behavior of tolerant rhizobia-legumes symbioses may constitute a very important pathway to increase soil fertility and quality and can represent a friendly biotechnological way to remediate cyanotoxins contamination in agriculture.

Chapter 3 - Climate Change Impact on Crop Productivity and Field Water Balance