No 1(124) (2024)

Kizlyar pastures are a vast part of the Western Near-Caspian region, which includes steppe and semi–desert landscapes of the south-east of Stavropol Region and north-west of Republic of Dagestan. Their phytocenoses have long been used in semi-nomad and sedentary livestock farming in the arid region, where the climate aridity and pasture overloading of livestock are the cause of land degradation. This in turn is accompanied by a reduction in their projective plant coverage, species composition and feed capacity. The purpose of the work is to assess the phytoecological and bioproductive state of natural forage lands in conditions of increased anthropogenic digression and manifestations of the reverse of it in the direction process of local demutation of desolate pasture ecosystems. The results of the research were obtained during the longterm (2003-2020) monitoring of the forage biocenoses state at 12 permanent sites (dedicated to livestock complexes and other nodal points in the steppe), and 37 temporary key sites (for expanding the database) on Kizlyar pastures, in the border regions of Stavropol Region (south-east) and Republic of Dagestan (northeastwest). They made it possible to extrapolate the ecological-productive and phytocenotic state of pastures on almost 400 thousand hectares of natural and about 15 thousand hectares of reclaimed pasture lands. The research novelty is the block of studies on the local demutation (reestablishment) of degraded phytocenoses manifestation during the formation of single-species synusias of the valuable Cýnodon dáctylon cereal plant in degraded pasture areas.

The study of the lanceolate ash growth in the dry oak forest of the Rostov Region conditions has scientific and practical significance, since this tree species is one of the main forest-forming species of the Kashar forestry. To date, forestry does not have data on the lanceolate ash growth in the natural forests of the Rostov Region steppe zone. This fact has determined the importance of this topic. The purpose of the research was to study the taxation indicators and lanceolate ash situation in dry oak forest conditions. The methods generally accepted in forest taxation were used. Tables of the ash growth course in diameter, height, volume and increment were compiled and regression equations of dependence on the above indicators were obtained based on the results of the research. Assessing the lanceolate ash situation in pure and mixed plantations, we came to the conclusion that with equal mixing in the composition of oak and ash tree species, the plantation is characterized as severely weakened, and pure and mixed plantings with a predominance of lanceolate ash are characterized as weakened. It was revealed that the optimal mixing in the dry ravine oak forest of the Rostov region conditions is 4Дч(oak)6Яз(ash).

The water stability of the soil structure is one of the most important factors determining its erosion stability. Sod-podzolic soils by their genesis are characterized by low stability to erosion. Therefore, it is relevant to develop agrotechnical and agrochemical techniques that promotes increasing the water stability of aggregates of eroded soils. The novelty of the presented work is a study of the effect of crop rotations with different soil protection capacity, as well as fertilizer systems in crop rotation on the water stability of the structure of eroded sod-podzolic soils to various degrees. It has been established that of the agrophysical and agrochemical properties affecting the structural and aggregate state of soils, the water stability of the soil structure depends mainly on the content of organic matter. The use of eroded soils in grass-grain crop rotations with saturation of perennial legumes up to 75% and the use of an organomineral fertilizer system and liming in crop rotation lead to an improvement in the water stability of the soil structure. It was found that the weighted average diameter of the water-bearing aggregates decreases with an increase in the degree of erosion degradation of soils. Cultivated crops do not have a significant impact on this indicator. There is only a tendency for its increase under alfalfa for the third year of use in the grass-grain crop rotation. There is also no reliable effect of fertilizer systems on the weighted average diameter of soil aggregates. The results obtained are the scientific basis for the development of soilprotective adaptive-landscape farming systems for different agrotechnological groups of lands subject to erosion degradation.

In the conditions of climate aridization, agricultural producers need alternative crops in their crop rotations, alongside traditional ones, to ensure a guaranteed harvest. The relevance of this research stems from the need to enhance the technology of grain sorghum cultivation through the application of growth regulators and organomineral fertilizers. The scientific novelty lies in the study of these growth regulators and their effect on grain sorghum productivity formation.

The field experiment was conducted in 2022 at the Gornaya Polyana Educational, Scientific and Production Center (ESPC) of the FSBEI HE Volgograd SAU, on light chestnut soils. The experimental design included three zoned hybrid variants and seven variants involving the use of growth regulators and organomineral fertilizers. Observations and analyses were carried out using standard agronomic methodologies.

As a result of the study, it was found that the combined use of the Fertigrain Start Plus growth regulator for seed treatment and the Fertigrain Foliar Plus organomineral fertilizer led to an average yield increase of 10–19% across all hybrids studied. Among them, the Bianca hybrid demonstrated the highest responsiveness to the treatment, producing yields ranging from 1.54 to 2.68 t/ha depending on the year’s conditions.

These findings are particularly relevant for agricultural producers in the districts of the Volgograd Region that face challenging climatic conditions and have a limited crop selection due to soil and environmental constraints.

High-quality seeds of valuable local and introduced species and forms with good hereditary properties should be used for the purposes of reforestation and protective afforestation. Pinus pallasiana has been one of the leading crops in the forest reclamation of the dry steppe zone of the south of the European part of Russia for a century. Pinus pallasiana should be considered a very adapted species, it has good growth, resistance to diseases and pests in steppe and dry steppe zones. Obtaining high-quality planting material is a very urgent task. The aim of the study was to evaluate the quality indicators of Pinus pallasiana seeds as an indicator of seed plantations stability. The object of research is Pinus pallasiana seeds collected from 3 sites in the Volgograd Region. The article summarizes the data on the growth and condition of the Pinus pallasiana species in artificial plantations, as well as the natural and geographical characteristics of three different sites located in the Volgograd Region. Data analysis demonstrated intraspecific differences in Pinus pallasiana plants. The X-ray method was used to determine the quality of the seeds. The highest quality seed material was selected from plot No 1 (89% of full-fledged seeds). The results obtained for germination capacity (85%) and germination energy (79%) from this site are consistent with the indicators obtained by X-ray of seeds, according to GOST 14161-86 and correspond to the 2nd class of seed quality.