Saratov Trans-Volga Region Research Articles

ВОДОПОТРЕБЛЕНИЕ, УРОЖАЙНОСТЬ И КАЧЕСТВО ЛУКА РЕПЧАТОГО В ЗАВИСИМОСТИ ОТ ПРИМЕНЕНИЯ ГУМИНОВЫХ УДОБРЕНИЙ ПРИ КАПЕЛЬНОМ ПОЛИВЕ В САРАТОВСКОМ ЗАВОЛЖЬЕ

Purpose: to study the features of humic fertilizer impact on water consumption, yield and quality of onions under drip irrigation in the dry-steppe zone of Saratov Trans-Volga region. Materials and methods. Field studies were carried out on dark chestnut soils in 2019–2022. The objects of the study were the zoned Chalcedony variety and fertilizers based on humic acids. Related observations and studies of water consumption, productivity formation and yield quality were carried out using generally accepted methods. Results. Research has shown that when maintaining a drip irrigation regime, which involves watering when soil moisture is reduced to 80 % of the lowest moisture capacity in the 0–30 cm layer, the total water consumption of onions on average over the years of the study amounted to 4102 cub. m/ha, average daily – 31 cub. m/ha. The humic fertilizer application contributed to a more economical use of moisture and irrigation water, as evidenced by a decrease in the water consumption coefficient by 7.1–23.3 %, and the cost of irrigation water to form a unit of marketable output by 15.9–24.0 %. Humic fertilizers also provided a significant yield increase – 4.9–15.31 t/ha (10–31 % higher than the control – without fertilizers). Conclusions: the humic fertilizer application, which have stimulating and adaptogenic features, when growing onions under the arid conditions of the Saratov Trans-Volga region with drip irrigation, is an effective technique that ensures more economical use of water resources and increases the yield of one of the leading vegetable crops – onions.

Агрофизические, технологические и климатические факторы, определяющие урожайность зерна яровой пшеницы в Заволжье

Purpose: to determine the share influence of agrophysical, technological, climatic factors and soil moisture on spring wheat grain yield in the arid conditions of the Saratov Trans-Volga region based on a complete correlation analysis of long-term field data. Materials and methods. To achieve this goal, an experiment with basic tillage with various implements according to the following scheme, was carried out: A₀ – with PLN-8-35 plow at 23–25 cm (control); A₁ – with plow PBS-10P at 23–25 cm; A₂ – with deep ripper SSD-4 (2017–2020), chisel plow PChM-4 (2021–2022) at 30–32 cm; A₃ – with a disk header BDM 7×3 PPKShKS at 10–12 cm. The research was carried out over a period of six years using generally accepted methods. Results. A complete correlation analysis of long-term data showed that the most significant influence on the spring wheat yield in the Trans-Volga region is exerted by precipitation during the growing season (24.1 %) and the hydrothermal coefficient (23.6 %). Air temperature determined this indicator by only 12.5 %. The share influence on the yield of soil density in the 10–30 cm layer was 2.9 %. The moisture content of the upper half-meter soil layer during the spring wheat tillering phase determined the yield by 14.8 %, and the lower one (50–100 cm) by 15.6 %. Conclusions. On average, over six years, the maximum yield of spring wheat Albidum 32 variety was obtained in variants with plowing (PBS-10P and PLN-8-35): 1.16 and 1.17 t/ha. Non-mouldboard cultivation with a deep ripper and chisel plow reduced this indicator by 8.5 %. Treatment of dark chestnut soil with a disk header reduced the spring wheat grain yield by 24.8 % relative to the control.

Estimation of sucrose solution saturation to assess the drought resistance of alfalfa varieties in the conditions of the Saratov Trans-Volga region

For normal alfalfa growth and development, a high supply of moisture is of great importance. The most stable fodder productivity is obtained on irrigated and floodplain lands. Though, water excess can also have a negative effect, especially on seed productivity. Alfalfa seeds can absorb large amounts of water, no less than their dry matter weight. Under a soil moisture shortage, low soil temperature and deep seeding, sprout emergence slows down. The main purpose of the current work was to analyze the effect of sucrose solutions of various saturations on seed germination and determine the desired saturation, which would be best used to estimate the relative drought resistance of alfalfa varieties under conditions of osmotic stress. The work was carried out at the “Ershovskaya ESIA, the branch of the FSBSI FARC of the South-East” in 2021–2022. There has been conducted trials to consider the effect of different solution saturations on the germination of alfalfa seeds of the varieties ‘Artemida’, ‘Yuzen’, ‘Virineya’, ‘Natali’ and ‘Sirena’. As a result of the study, there was shown that, depending on the varieties and saturation of the solution, seed germination varied from 4 to 100 %. The variety ‘Yuzen’ showed maximum seed germination of 75.2 % and a minimal decrease in germination with increasing osmotic pressure relative to other varieties. At the highest sucrose solution saturation (16.6 %), the best figures were produced by the varieties ‘Artemida’ and ‘Virineya’. Our trial has identified that to determine the relative drought resistance of alfalfa varieties, it was most effective to use sucrose solutions with a concentration of 7.4 and 16.6% for a more reliable result.

Abundance and demographic structure of the great bustard (<i>Otis tarda</i>) (Otididae, Aves) population at lek areas in the Saratov and Volgograd Trans-Volga region

The results of our studies of the great bustard population in the Saratov and Volgograd Trans-Volga region are presented. For the first time in this territory, censuses of the numbers of bustards were carried out in their lek areas in the spring for 3 years. This made it possible to obtain more reliable data on the numbers of individuals of this species, as well as on the demographic structure in the model area and compare them with those obtained during autumn population counts. In our opinion, as a result of agriculture intensification, the nesting habitats of the bustard have been sharply reduced, which was caused by changes in the structure of crop areas and the massive use of pesticides. In the absence of necessary protection measures, this has led to a reduction in the numbers of birds in the Saratov Trans-Volga region by almost 10 times over 20 years. This trend is observed throughout almost the entire world range of the great bustard, where there are no long-term effective measures aimed at preserving the natural habitats of the species. In the Trans-Volga region, the number of lek areas has decreased by approx. half and the numbers of individuals of the species in the remaining leks have decreased. The demographic structure of the bustard population when studied in lek areas shows a significant predominance of males over females, which contradicts the stability of the population. Due to the reduction in the number of habitats suitable for bustards to nest, the success of their reproduction has significantly decreased. Spring treatment of crop areas with pesticides by ground and aerial methods coincides with the nesting period of birds, which is a powerful factor of disturbance and leads to the loss of clutches. Females whose clutches have been preserved, have the problem of acute food shortage after their chicks hatched, which also leads to elimination of some part of the broods.

Features of the Population Dynamics of Larks (Alaudidae, Aves) in the Semi-Desert Zone of the Saratov Trans-Volga Region

Features of the Population Dynamics of Larks (Alaudidae, Aves) in the Semi-Desert Zone of the Saratov Trans-Volga Region

Agrobiological and agrochemical aspects of increasing the yield of sunflower hybrids in the Saratov Trans-Volga region


 Abstract. The article provides an analysis of agrobiological (hybrids, seeding rate) and agrochemical (mineral fertilizers) aspects of increasing the yield and quality of sunflower in the Saratov Trans-Volga region. The results of three-year studies have established that the cultivation of the sunflower hybrid P64LE25 using Ammophos at a dose of 80 kg/ha before the main tillage and Sulfoammophos at a dose of 50 kg/ha when sown at a seeding rate of 60000 pcs. germinating seeds per 1 ha ensures the maximum yield of sunflower oilseeds - 2.02 t/ha. Increasing the seeding rate from 55 thousand to 65 thousand seeds/ha reduced the planting density and field germination by 3.2–3.4%. Mineral fertilization reduced field germination by 0.7–1.5%. The cultivation of the late-ripening hybrid P64LE25 increases the yield of oilseeds by 0.28 t/ha (by 18.8%), oil content by 2.5% compared to the mid-early hybrid P64F66. The seeding rate of 60000 pcs/ha increases the yield of the studied hybrids by 0.23 t/ha (by 15.4%). Mineral fertilization (N8P10S6) provides an increase in the yield of sunflower oil seeds - 0.24 t/ha (by 15.9%), and oil content by 0.4%.

Restoration of moisture reserves in the soil in the grain-fallow crop rotation before sowing spring and winter wheat in the Saratov Trans-Volga region

As a result of many years of field experiments, it has been established that in the Saratov Trans-Volga region, after autumn-winter precipitation in a meter-long layer of soil, moisture reserves corresponding to the lowest moisture capacity are not restored. In a clean fallow after sunflower, soil moisture reached maximum values of 81–86% HB in three years out of six, 70–76% HB in one year, and less than 70% of minimum moisture-holding capacity in two years. On average, over six years, soil moisture changed from 72% at minimum tillage to 76% of minimum moisture-holding capacity at deep non-moldboard. During the period of sowing winter wheat in clean fallows, on average for six years, soil moisture remained at the level of 61.9–65.8% of minimum moisture-holding capacity. Such insignificant reserves of moisture in the soil without September precipitation do not provide friendly seedlings and normal development of winter wheat. Before sowing spring wheat after the predecessor - chickpea, the highest humidity reached only 75–82 % of minimum moisture-holding capacity for three years. The minimum values of soil moisture at the level of 57–64 % of minimum moisture-holding capacity were for two years. Experimental data obtained over six years (2017–2022) show that a 10–12 cm main tillage reduces the yield of winter wheat by 0.37 t/ha, or by 14.6%, of spring wheat by 0, 29 t/ha, or by 24.8%.

Адаптивное нормирование орошением

This article deals with the problem of the widespread development of irrigation in the territory of the Saratov Trans-Volga region, which led to the deterioration in the reclamation state of lands, which can be suspended by developing perfect irrigation rationing through automated programs. Therefore, the issue of increasing the effi ciency of irrigation rationing by determining the total water consumption of plants, taking into account the water regime of the soil, the state of the active surface, weather conditions and biological characteristics of the crop is relevant. The article presents mathematical dependencies used to develop an automated system for adaptive irrigation rationing on the example of alfalfa culture in the conditions of the dry steppe Trans-Volga area of the Saratov region. When choosing a method for determining evaporation, a comparison was made of the results of calculating evaporation using the methods of N.N. Ivanov and the Budyko-Zubenok method. The known dependences of the dynamics of the water regime of the calculated soil layer, water consumption, coeffi cients characterizing the biological characteristics of the crop in the process of growth and development, the state of the active surface, the calculated irrigation rate, the condition for maintaining the moisture reserves of the active soil layer in the optimal range, ensuring minimal water loss and optimal moisture supply of the crop are given that form the basis of the automated calculation program for adaptive rationing by irrigation. Adaptive rationing by irrigation consists in determining the total water consumption by an agricultural crop, taking into account the water regime of the soil, the state of the active surface, meteorological information and the biological characteristics of the plant (crop). A program of adaptive irrigation regulation is proposed on the example of a crop – alfalfa, which will improve the efficiency of irrigation water use in the Saratov Trans-Volga region, and as a result will improve the ecological situation in this region.

Features of the population dynamics of larks (Alaudidae, Aves) in the semi-desert zone of the Saratov Trans-Volga region

The paper presents the results of our long-term monitoring of the family of larks (Alauda arvensis L., Melanocorypha calandra L., M. leucoptera Pallas, M. yeltoniensis J. R. Forster and Calandrella rufescens Vieillot) in the semi-desert zone of the Saratov Trans-Volga region. Bird censuses were carried out at 4 key sites on permanent routes during the nesting period, the total length of the census transects was 792 km. Statistical indicators of population dynamics were calculated, namely: the growth rates (Tnp.) and average density values (ind. / 100 ha) of each lark species. A statistical multivariate factor analysis (F-test) was carried out, with the help of which we were able to reveal the influence of a whole range of factors on the lark density dynamics. Changes in habitat conditions at the key areas (Fcrit. = 1.30, p = 0.003), as well as weather factors (Fcrit. = 1.39, p = 0.004) of particular years, have a significant impact on the density dynamics of larks. Evaluation of the variance showed heterogeneity of the sample (St = 0.119, p = 0.006), therefore, the average densities of larks differs significantly from each other. Thus, the structure of the lark community and the annual density of each species are the result of the environmental conditions of the habitats at each key site, and the weather conditions of particular years.

Characteristics of the great bustard (Otis tarda) (Otididae, Aves) habitats in the Trans-Volga region according to food availability during the chick rearing period

The results of our studies of potential nesting sites for bustards in the Saratov Trans-Volga region are presented. Characteristics of plant communities, as well as the quantitative and qualitative composition of arthropods in these areas, are given. Specific materials obtained in 2017–2021 at 6 plots are given, namely: crops of winter wheat, millet, and sunflower; fallows of various ages; and young (2nd stage) and old virgin lands. The obtained results are compared with the data of previous years. The obtained results on the state of the forage base of bustards allow us to conclude that loss of nesting habitats by birds of this species has actually occurred. Those areas, where, despite the decrease in the abundance of insects, there are still enough of them to feed the chicks, are not used by bustards as nesting stations. These are fallows of various ages and virgin lands. The lack of a sufficient number of arthropods necessary for feeding chicks in those places where bustards prefer to nest, namely, cereals crops, leads to catastrophic consequences for reproduction, and, consequently, the survival of the species. The numbers of large orthoptera and beetles in winter crops, reflecting biomass indicators, have decreased by 10 times compared to 2000, during the period of extensive agriculture. The intensification of agricultural production, the use of pesticides on various crops, as well as the change in the structure of crop rotation are the main causes for the insufficient food supply during the period of rearing chicks. The results obtained give grounds to believe that the number of bustards will continue to decline due to the inability to raise their offspring as a result of the lack of food supply.

Condition and growth of pedunculate oak (Quercus robur L.) in irrigated forest belts of Saratov Trans-Volga steppe

The research aim was to establish the regularities of condition and growth of pedunculate oak (Quercus robur L.) in the irrigated forest belts in the steppe of Saratov Trans-Volga Region. The study object is a system of forest shelter belts under conditions of irrigation of dark chestnut soils of Saratov Trans-Volga steppe with tree species of the main and accompanying purpose - pedunculate oak, lanceolate ash (Fracsinus lanceolata L.) and squat elm (Ulmus pumila L.). The research in the field and materials processing were carried out in accordance with the methodology of specialized research institutes and leading scientists in the field of agroforestry. Forest belts located on agricultural land protect crops from the negative effects of drought and dry winds, optimize snow distribution in winter and irrigation regimes for crops during the growing season, and increase the crops productivity. Irrigation has the most important positive effect on growth and condition of tree species in forest belts and, as a result, on durability and reforestation efficiency of forest belts. The studies have shown that the average height and diameter of oak in the. irrigated forest belts mixed with different species are higher than those without irrigation by 15-26% and 34-39%, respectively. The oak growth in height in irrigated areas of forest belts exceeds its growth in height in areas of forest belts without irrigation by 1.5 times. The vital condition of oak in the irrigated forest belts is characterized by the prevalence of “slightly oppressed” (48%) and “healthy” oak trees (40%).

Influence of microfertilizers on water consumption ratio and yield of chickpea in the Saratov Trans Volga region

The article shows the influence of the main tillage and mineral fertilizers with microelements on the water consumption coefficient and the yield of chickpea grain in the Saratov Trans-Volga region. On average, over three years in chickpea crops, the highest total water consumption was after subsoil tillage - 1240 m3 / ha, which exceeded the control by 64 m3 / ha. Minimal tillage led to an increase in the water consumption coefficient by 533 m3 / t, or 31%. After subsoil tillage it increased by 372 m3 / t, or 22% relative to conventional tillage. Foliar top dressing with microfertilizers in the chickpea branching phase reduced the water consumption ratio by 88–236 m3 / t, which amounted to 4.3–11.4%. A decrease in the depth of the main processing to 10–12 cm led to a 23.5% decrease in the yield of chickpea. Subsoil tillage reduced the yield by 10.3%. Combined soil cultivation did not provide a significant increase in yield relative to control. Foliar feeding of chickpeas in the branching phase with micronutrient fertilizers increases the yield by 5.1–11.9%.

Data bank of irrigation ponds of the Saratov region

The article is devoted to the issue of improving the quality of operation of small reservoirs of the left-bank districts of the Saratov region through the development and implementation of an automated data bank of their safety parameters. It provides a generalized scheme for the functioning of an automated databank, as well as the structure of the database, which should include 27 relational files containing all the necessary information for declaring the safety of hydraulic structures of reservoirs and calculating the harm to the population and subjects of economic and economic activity, various natural and man-made objects in case of accidents. The creation of such an automated data bank will improve the quality of monitoring the condition and management of hydraulic structures of the reclamation systems of the Saratov Trans-Volga region and will pay off in 5 years.

Share influence of water-physical properties of soil and weather conditions on the yield of chickpea in the Saratov Trans-Volga region

Five-year observations of the water-physical properties of the soil showed a significant increase (by 14.5%) in the density of the arable layer after the minimum tillage, where this indicator was 1.26 g / cm3. On the control and on the variant with combined tillage, the soil density was minimal - 1.10 g / cm3. The water permeability of the dark chestnut medium loamy soil varied from 78.7 mm / h (at minimum tillage) to 132.5 mm / h (at the dump). Before sowing chickpeas, higher soil moisture in the meter layer was after non-moldboard tillage - 16.7% of the mass of absolutely dry soil, which is 0.4 and 0.9% higher relative to the control variant and minimum tillage, respectively. The maximum yield of chickpea grain (0.94 t / ha) was after the combined processing of the Boykov PBS-8M plow to a depth of 23–25 cm. Minimization of the main tillage reduced the yield by 18.7% compared with the control. Calculation of the share influence of the studied factors on the yield of chickpea grain showed that the determining factors are the moisture content of a meter layer of soil in the branching phase, the amount of precipitation during the growing season, soil moisture before sowing, and the density of the arable layer.

ЭФФЕКТИВНОСТЬ ИСПОЛЬЗОВАНИЯ ПОЛИВНОЙ ВОДЫ ПРИ ВОЗДЕЛЫВАНИИ КОРМОВЫХ КУЛЬТУР

The article considers the problem of effective use of irrigation water in the cultivation of fodder crops on irrigated lands of the Saratov Trans-Volga region. The main costs in the cultivation of crops fall on the supply of water, so its efficient use becomes one of the main tasks in irrigation reclamation. The possibility of cultivation in this natural and climatic zone of a large number of various forage crops is shown, the features of their cultivation on irrigated lands are considered. Data on the distribution of fodder crops by species are given, the possibility of more efficient use of irrigated lands by introducing intermediate crops into crop rotations is shown, which will allow obtaining a greater yield of fodder units per irrigated hectare. The issue of methodology for conducting water-balance studies on irrigated lands and the determination of individual elements of the water balance equation is considered in detail, their relative values are given. The irrigation regimes for alfalfa, Sudanese grass and sorghum are considered, irrigation norms are given for the years of cultivation, as well as the number of irrigations. The difference in irrigation regimes is substantiated, both for different crops and for different years of research, depending on the natural moisture supply. The values of coefficients of water consumption and use of irrigation water for the considered fodder crops are calculated according to the values of productivity and irrigation norms. In conclusion, a conclusion was drawn about the most rational choice of crops for cultivation in this natural and climatic zone, while maintaining a favorable ecological and reclamation state of irrigated lands and efficient use of irrigation water.

Habitat Structure and Abundance Dynamics of Marmota bobak Müller, 1776 (Sciuridae, Mammalia) in the Saratov Region at the End of the 20th–Start of the 21st Centuries

The paper presents data on the abundance of bobak marmot (Marmota bobak Muller, 1776), obtained from 1987 till 2019. All censuses were performed according to one technique developed by us in the late 1980s. During these long-term investigations, the structure of the bobak marmot areal in the Saratov region was studied. The dynamics of its numbers is described, and its trends for individual groups of districts were revealed, distinguished by trends, the time of the appearance of new settlements as a result of reintroduction after a prolonged depression in the numbers caused by both plowing of the steppes and the well-known events of the 1920s, 1930s and 1940s, when the bobak marmot provided the survival of some part of the population. It has been established that the population peak in the indigenous settlements that have been existing from the end of the Pleistocene–the beginning of the Holocene, was in 1980–1990. New settlements arise in the territories where the marmot was reintroduced, and the species abundance continues to grow. This, first of all, refers to the western slopes of the Volga Upland and the Oka-Don plain, formerly inhabited by marmots. An increase in the numbers of the Kazakhstan subspecies of the bobak is observed at the eastern end of the Syrt plain and on the spurs of the Common Syrt in the Saratov Trans-Volga region. The genetic studies of steppe marmots by R.V. Naumov (2019) on the right Volga bank of the Ulyanovsk region showed that a genetically homogeneous population lives on the vast territory of the Volga region. This casts doubt on the assumption of the existence of the Kozlovi subspecies of the bobak marmot in the local territories of the Voskresensk, Volsk and Khvalynsk districts of the Saratov region, which served as the ground for its inclusion into the new edition of the Red Data Book of the region, which we consider unreasonable (Resolution…, 2019).

Habitat Structure and Abundance Dynamics of Marmota bobak Müller, 1776 (Sciuridae, Mammalia) in the Saratov Region at the End of the 20th – Start of the 21st Centuries

The paper presents data on the abundance of bobak marmot (Marmota bobakMüller, 1776), obtained from 1987 till 2019. All censuses were performed according to one technique developed by us in the late 1980s. During these long-term investigations, the structure of the bobak marmot areal in the Saratov region was studied. The dynamics of its numbers is described, and its trends for individual groups of districts were revealed, distinguished by trends, the time of the appearance of new settlements as a result of reintroduction after a prolonged depression in the numbers caused by both plowing of the steppes and the well-known events of the 1920s, 1930s and 1040s, when the bobak marmot provided the survival of some part of the population. It has been established that the population peak in the indigenous settlements that have been existing from the end of the Pleistocene – the beginning of the Holocene, was in 1980–1990. New settlements arise in the territories where the marmot was reintroduced, and the species abundance continues to grow. This, first of all, refers to the western slopes of the Volga Upland and the Oka-Don plain, formerly inhabited by marmots. An increase in the numbers of the Kazakhstan subspecies of the bobak is observed at the eastern end of the Syrt plain and on the spurs of the Common Syrt in the Saratov Trans-Volga region. The genetic studies of steppe marmots by R. V. Naumov (2019) on the right Volga bank of the Ulyanovsk region showed that a genetically homogeneous population lives on the vast territory of the Volga region. This casts doubt on the assumption of the existence of the Kozlovi subspecies of the bobak marmot in the local territories of the Voskresensk, Volsk and Khvalynsk districts of the Saratov region, which served as the ground for its inclusion into the new edition of the Red Data Book of the region, which we consider unreasonable (Resolution..., 2019).

The influence of soil cultivation methods and agrochemicals on the productivity and quality of winter wheat grain in the Saratov Trans-Volga region

The article describes the effect of mineral fertilizers, a growth regulator, a growth stimulant and primary tillage methods on the yield and quality of winter wheat grain. A comparative analysis of the prevailing weather conditions by the amount of precipitation during the years of research with a long-term climatic norm and optimal values during the growing season of winter wheat to obtain maximum yield in the Saratov Trans-Volga region was carried out. As a result of research, it was found out that minimizing the main tillage in pure fallow crops for winter wheat reduces its yield by 10.5%. The maximum yield of winter wheat is provided by the combined processing (2.26 t/ha), which exceeds ploughing (control) by 3.2%. Deep subsurface processing did not provide a reliable increase in winter wheat productivity (+0.02 t/ha). The main tillage methods did not affect the protein content in the grain of winter wheat, and the amount of dry gluten decreased by 0.6% after minimal processing and 0.7% after subsoil tillage compared to the control. Spraying winter wheat crops with mineral fertilizers increased productivity by 3.7–8.8%, growth stimulator by 4.2%. The growth regulator (Giberelon) did not affect the productivity of winter wheat in the arid conditions of the Saratov Trans-Volga region. The maximum increase in protein and gluten was provided by mineral fertilizers Megamix No. 10 - 0.4; 1.7% and Mikrovit - 0.5; 1.6% and growth promoter GSN - 2004 - 0.5; 1.7%.

Responsibility of sunflower hybrids to minimize the main tillage of soil in the Trans-Volga region

Peculiarities of changes in soil moisture at various methods of main tillage before sunflower sowing and in the phase of “beginning of flowering” are considered. As a result of two-year observations, it was established that, in the arid conditions of the Saratov Trans-Volga region, before the sunflower sowing, the maximum soil moisture of a layer of 50–100 cm was after non-mold deep cultivation, which exceeded the plowing by 0.2–0.7%, and the minimum one by 0.7– 2.0% of the mass of absolutely dry soil. In the phenological phase of the “beginning of flowering", the best water regime was in 2018 after treatment with SSD-4 by 30–32 cm, and in 2019 in the control 1. Minimization of the main tillage reduces the yield of sunflower oilseeds in comparison with the dump cultivation by 32.8–46.2%. Deep subsurface cultivation increases the productivity of sunflower by 3.1–7.5%. The most productive sunflower hybrids for the Saratov Trans-Volga region are from the group of early ripening crops - Svetoch (1.56 t / ha), mid-early - the EU Savana (1.63 t/ha), mid-ripening EU Generalis SL (1.47 t/ha).

On the distribution of wild relatives of cultivated plants in the Saratov Trans-Volga region (collecting mission of 2017)

The relevance of this study is determined by the geographical specificity of the Saratov Trans-Volga region characterized by climatic conditions that are original for Eastern Europe. In order to display the specificity of this region in terms of CWR, a collecting mission was conducted to the Saratov Trans-Volga region in June 2017, encompassing four botanical and geographical areas located in the steppe zone, namely Eruslansky, Zavolzhsky, Sinegorsky, and Zairgizsky. 36 habitats have been investigated; 38 seed samples and 166 herbarium specimens (177 sheets) collected. New locations for the biennial vetсh ( Vicia biennis L.) and Allium delicatulum Siev. ex Schult. & Schult. f. have been discovered.