№ 2 (2023)

New approaches to the study of succession dynamics are based on the original concept of system dynamics, which was used in the development of simulation models reflecting the dynamics of pasture ecosystems. The temporal dynamics of the soil and vegetation cover of the natural pastures of the Black Lands of Kalmykia reflects the degradation processes that are studied by simulation modeling. The processes of pasture degradation in the subarid belt of Southern Russia were described by ordinary differential equations. This concept is the basic one in the development of simulation models. The dynamics of changes in effective coatings for phytocenoses of pastures of Black Lands in the process of degradation was traced from the original pastures to complete desertification. Analytical solutions for various conditions of succession dynamics in the degradation of natural pasture lands are a convenient test for assessing the adequacy of simulation modeling. The initial time periods of space observations of effective coatings of phytocenoses were used to parametrize simulation models. The models are implemented in the AnyLogic simulation system. The model development process is based on visual programming using the graphical user interface. Information flows in the Anylogic environment are redistributed over time through a system of storage devices interconnected by an oriented graph of the model. A computational experiment demonstrating simulation results with different parameters was used for an indicative (qualitative) assessment of ecosystem sustainability. The results of analytical modeling using ordinary differential equations and simulation modeling showed a high identity. The study of the dynamics of pasture ecosystems using a variation experiment demonstrates the possibility of visual (cognitive) selection of the parameters of the model that determines the conditions of stationarity of pasture ecosystems. Studying the dynamics of successions of pasture phytocnoses by this method opens up new opportunities for solving problems of optimal use of biological resources and sustainability of pasture ecosystems.

Studies have been carried out to study the effectiveness methods of basic tillage with the use of chemicalization and biologization means on the yield of corn and the content of mobile phosphorus in the arable (0-25 cm) layer of typical chernozem underlain by pebbles. Object of research: the soil of the experimental plot is a typical heavy loamy, medium-thick, low-humus chernozem, underlain by pebbles with an average content of humus (according to Tyurin) in the arable layer - 3.6%, mobile phosphorus and potassium (according to Machigin) - 15 and 300 mg/ kg respectively. The reaction of the soil environment (by the potentiometric method) is neutral (рНKCl= 7.1). Corn for grain (hybrid Pioneer 9678) was placed in a grain-row crop rotation with alternating crops: wintering peas - winter wheat - corn for grain - spring oats. In the scheme of the experiment, the following variants were studied: reception of the main tillage (factor A) - plowing to a depth of 25 ... 30 cm, disking to a depth of 10 ... 15 cm, chiselling to a depth of 30 ... 40 cm; fertilizers and a biological product according to the aftereffect of green manure (factor B) - without fertilizers and a biological product by aftereffect of green manure, fertilizer (diammophoska, ammonium nitrate) and a biological product (V417) by aftereffect of green manure (spring rape): N120P60K60 + green manure, V417 + green manure, N120P60K60 + V417 + green manure. On average, for two years, among the methods of the main tillage during disking, the highest yield of corn for grain was obtained - 4.75 t/ha with the content of mobile phosphorus in the arable soil layer - 21 mg/kg (63 kg/ha). According to the effect of chemicalization and biologization means for different soil tillages, the use of the biological product V417 by aftereffect of green manure (spring rapeseed) against the background of disking provided the highest average yield of corn for two years - 5.10 t/ha with a content of mobile phosphorus of 21 mg/kg (63 kg/ha). On average, over two years, the highest content of mobile phosphorus - 26 mg / kg (78 kg / ha) with its balance - 60 kg / ha, with an intensity of 236%, was facilitated by disking with the combined use of fertilizers and the biological product V417 according by aftereffect of green manure. At the same time, the parameters of the variants during plowing and chiselling were exceeded by 1.5 ... 2 times. In addition, an increase in the content of mobile phosphorus in the arable layer of soil from a low (11...15 mg/kg) to an average level (16...30 mg/kg) was achieved.

The purpose of the research is to identify and recommend for production or practical breeding varieties and hybrid potato material of various genetic and geographical origin, combining high yield, field resistance to mosaic viruses and adaptability to stressful abiotic environmental factors, optimize and improve the efficiency of field evaluation of potato varieties. The research was carried out in 2019-2021 in the Bezenchuk district of the Samara region. 2019 was characterized by a spring drought, and in 2020 and 2021 there was a spring-summer drought. The hydrothermal coefficient was 0.45; 0.47 and 0.61, respectively. In conditions of high temperatures and insufficient moisture, 36 new and promising potato varieties of domestic selection were evaluated according to a complex of economically valuable characteristics. The standards were the varieties Arosa, Gala, Zhigulevsky and Udacha. The experimental material was planted in four repetitions. The number of plants in repetition is 50. The predecessor is spring wheat. The soil of the experimental site is terraced chernozem, ordinary, low-humus, medium-thick, heavy loamy. High yields were characterized by medium-early varieties Krasa Meschery, Debut and Sudarinya, which exceeded the Gala standard by 9.9 t/ha, 4.8 t/ha and 2.8 t/ha; medium-ripened Siversky and Alaska (8.6 and 5.0 t/ha higher than the Zhigulevsky standard, respectively), as well as early-maturing Terra variety (5.0 t/ha above the standard Udacha) The same varieties have high indicators of field virus resistance at the level of 7...9 points to the most harmful X and Y viruses in the conditions of the Middle Volga region. Three main components that have the most significant impact on the variability of the studied parameters are identified. It is shown that field virus resistance was the main limiting factor of yield for the studied set of varieties under conditions of elevated air temperatures and insufficient humidification. The share of the first component accounted for 34.6 % of the variation of signs. It includes, with maximum loads of -0.801, -0.640 and -0.604, respectively, the yield and resistance to potato viruses X, S, and M. The productivity of the studied set of potato varieties was to the greatest extent due to field resistance to viruses X, S, M and, to a lesser extent, to virus Y.

The aim of the study was to determine the differences in the content of amino acids in wheat grains of the world collection of VIR in the agro-climatic conditions of the Republic of Tatarstan and to search for sources of increased content of essential amino acids for the use of these data in breeding. The study was conducted in 2021-2022 at the experimental base of the Tatar Research Institute of Agriculture of the Kazan Scientific Center of the Russian Academy of Sciences, located 15 km away from Kazan, the soil of the experimental site is gray forest. 354 samples of spring wheat were studied. The determination of the content of seventeen amino acids and protein in wheat grain was carried out using the near-infrared spectroscopy method on the DS 2500F device from FOSS. The protein content in the grain has a significant effect on the amount of essential acids. The correlation between the protein content and the amount of essential acids in wheat grain is high in 2021. r = 0.91 ± 0.02 and average in 2022. r = 0.69± 0.04. The highest content of glutamine in wheat grain was noted - up to 2.22 % and proline - up to 1.55 %. The source of high grain content of histidine 0.38- 0.40 %, isoleucine 0.53-0.54 %, lysine 0.61-0.62 %, methionine 0.28-0.30 %, phenylalanine 0.66-0.67 %, threonine 0.52-0.56 % and tyrosine 0.31-0.36 % was the Ranee sample (k-26982). The Panifor sample was a source of high grain content of cysteine 0.58-0.63 %, histidine 0.39 % and threonine 0.51-0.58 %. The Arrino sample (k-65995) is a source of high grain content of leucine 0.82-0.91 %, tyrosine 0.31-0.34 % and valine 0.75-0.78 %. According to the lysine content in protein (grams of amino acid per 100 grams of protein), samples Ranee (k-26982) - 3.63-3.66 and NIL Avocet Yr15 (k-66241) - 2.86-4.52 were isolated. According to the content of methionine in the protein, samples of Uffo (k- 66798) - 1.80-1.8 and Fiorina (k-66034) - 1.70-1.91 were isolated. According to the threonine content, three samples Ranee (k-26982) - 3.04-3.36, Panifor (k-66039) - 3.09-3.20 and Cub (k- 62510) - 3.07-3.20 were distinguished. The source of the high tryptophan content in the protein were samples Ethos (k- 65002) - 2.00-2.27, Tulaykovskaya 108 (k- 65452) - 2.01-2.26 and Ekada 109 (k-66239) - 2.07-2.14.

In sweet cherry varieties cultivated in foothill Dagestan, to establish their selection and technological priorities, the mineral composition was studied, the content of sugars and acids was determined by generally accepted analysis methods. The subjects of the study were fruits of 8 introduced and 12 local breeding varieties of sweet cherries, which, depending on the variety, contained: potassium 80.6- 312.5; calcium 10.0-35.6; sodium 9.4-48.9; magnesium 7.7-21.2; phosphorus 25.6-55.1; iron 0.19-1.02; copper 0.08-0.63; manganese 0.11-0.68 and zinc 0.31-0.94 mg%. The best in terms of the total supply of macroelements in fruits were varieties: Gudzon - 427.7; Valeriy Chkalov - 335.2; Vinka - 320.8; Lezginka- 294.6; Durona de Vinola (sek.) - 284.3; Dagestanskaya chernaya - 271.4 and Pozdnyaya Lermontova - 271.0 mg%. A large amount of microelements (2.18-1.79 mg%) were found in the fruits of the varieties Valeriy Chkalov, Gudzon, Durona de Vinola (sek.), Krupnoplodnaya, Bigarro Krainskogo, Dagestanskaya rannyaya, Dagestanskaya chernaya and Pozdnyaya Lermontova. Most varieties of sweet cherries: Polyanka, Gudzon, Vinka, Romantika, Bigarro Krainskogo, Buynakskaya chernaya, Lezginka, Leningradskaya gvardeyskaya and Pozdnyaya Lermontova, the total amount of sugars ranged from 11.2-12.8 %, and the concentration of acids was 0.63-1.10 %. The most promising for the optimization of the industrial variety of sweet cherries in the conditions of Dagestan, the use in selection work and the design of new specialized food products, were the varieties Valeriy Chkalov, Vinka, Durona de Vinola (sek.), Gudzon, Krupnoplodnaya, Bigarro Krainskogo, Dagestanskaya chernaya, Lezginka and Pozdnyaya Lermontova, distinguished by the greatest ability formation of mineral substances, sugars and acids in fruits.

In recent years, Russia has seen a steady increase in grain crop yields. A positive trend in meteorological conditions is often considered as the reason for this phenomenon, but there is almost no strong scientific evidence for it. The aim of investigation was to analyze changes in the potential (climatic) grain yields in the country for the period from 2000 to 2022. For this purpose, the simulation model of plant growth WOFOST was used, which allows assessing the impact of all meteorological parameters in a comprehensive manner. The assessment was carried out for a network of representative points (42 points) in different regions of the country for grain crops, taking into account daily meteorological parameters and soil type. Modeling was conducted at the level of potential yield, which takes into account the variation of meteorological parameters only, and it is believed that the limiting influence of other factors on the yield is absent. As a result of the analysis, it was found that the trends of potential yields have different direction in different regions of the country. The trend towards more favorable meteorological conditions for grain crops is observed for the North Caucasus, the lower Volga region, Western Siberia and the Far East, while in the Central and Central Black Earth districts, the upper Volga region, as well as in the south of Central Siberia in recent years there is a drop in the potential yields. The growth of grain yields in recent years agrees well with the trend of changes in agrometeorological conditions in most grain-producing regions of the country. Unidirectional trends in meteorological potential and statistical yields are absent only in the regions of central European Russia, where the role of the climatic factor in grain yield fluctuations is less significant, and where one can assume the effect of measures taken by the government of the country to support and develop agriculture.

Impact of genus Pseudomonas bacteria on fractional composition of nickel compounds in artificially contaminated agro-gray soil and yield of spring wheat was studied in pot experiment. Plants were grown up to booting stage with NiCl2·6H2O contamination at a rate of 300 Ni/kg of soil against background of NPK fertilization. Distribution of nickel in soil fractions isolated by the method of successive selective extractions has been established. Nickel content in plants after combustion in mixture of HNO3:HClO4 (2:1)and in soil fractions was determined by inductively coupled plasma emission-optical spectrometry. Application of bacteria increased plant resistance to elevated nickel concentration and increased yield, significantly reducing heavy metal phytotoxicity. Bacteria increased nickel content in exchangeable and specifically sorbed fractions and, to a lesser extent, in fractions associated with organic matter and ferruginous minerals, and reduced metal content in residual fraction. Bacteria increased nickel uptake from soil by plant shoots due to increase in yield, without changes or increase in plant metal content. Thus, bacteria increased phytoextraction - cleaning soil from heavy metal. Nickel uptake by plants was increased due to increase in its bioavailability, mainly in exchangeable and specifically sorbed fractions.