The influence of the groundwater level (GW), vegetable crop rotation and mineral fertilizers on the change in the composition of organic matter of medium-thick peat soil was determined. The study was conducted on lysimeters with an adjustable level (0.5; 1.0; 1.5 and 1–2.0 m) of groundwater occurrence; in a vegetable-feed crop rotation spread in time and space; under perennial grasses without prior cultivation of annual crops. It was established that in the arable layer (0.2 m) of peat soil, the bitumen content at GW level of 0.5 m was lower by 1.65% than at a depth of 1.0 m, and by 4.34% than at a depth of 1.5 m. The maximum amount of water-soluble substances (5.68%) and substances hydrolyzable by 2% HCl (34.25%) was established at GW level of 0.5 m. It was 1.2 and 3.4–3.8% higher than at groundwater level of 1–1.5 m, respectively. With GW level of 1.5 m, the amount of humic acids decreased by 4.5% compared to their occurrence at a depth of 0.5 m. The amount of fulvic acids in the arable layer depends on the GW level (r = 0.79). The content of substances hardly hydrolyzable by 80% H₂SO₄ in the arable layer decreased from 2.82 to 2.31% with an increase in groundwater depth from 0.5 to 1.5 m. It was observed that the amount of lignin decreased with an increase in groundwater depth from 0.5 (6.66%) to 1.5 m (5.30%). Five- year cultivation of crops in the vegetable-feed crop rotation did not lead to significant changes in the composition of the organic matter of peat. Grassing of peat soils with perennial grasses without sowing pre-crops ensures preservation of peat organic matter and prevents its substantial transformation. Mineral fertilizers reduce the rate of accumulation of hardly-hydrolyzable and non-hydrolyzable forms due to more severe oxidative-hydrolytic conditions in the soil and because of an increase in the amount of fresh plant material as a result of crop and root residues.

Field experiments (2001–2005) were carried out to create optimal schemes for sowing mixtures of perennial grasses in the forest-steppe of Western Siberia. Objects of research were Krasnoobsky oats, Eastern galega Gorno-Altayskaya 87, awnless brome Antey. The soil of the plots was medium thick, medium loamy leached chernozem. The experiment was carried out in two layouts spread in time and in space. Grasses were sown under the cover of Krasnoobsky oats. Awnless brome was sown across galega in the first ten days of May. Seeding rate of awnless brome was 3.0; 4.5 and 6.0 million germinating seeds per hectare. Recordings of yield were made according to standard methods. The highest yield of galega dry mass was achieved when it was sown in rows with awnless brome planted with inter-row spacing of 15 cm (it was higher than with 30 cm inter-row spacing by 1.16 t/ ha and 0.63 t/ha, respectively). In the variant “three rows of galega + a row of awnless brome” (3 : 1), the yield of dry mass of the mixture in two cuttings was higher by 5.7 and 2.1% than when they were sown with every other row skipped. The total yield for two cuttings exceeded single-species crops of galega by 0.48–2.03, and awnless brome by 2.15–2.54 t/ha. A tendency towards a decrease in the yield of dry mass in single-species crops of galega with an increase in row spacing was noted. In mixtures sown at the same time according to the 3 : 1 scheme, the yield of dry mass was 5.14 t/ha in the first mowing and 4.05 t/ha in the second. This is higher than in the mixture sown according to the scheme “a row of galega + a row of awnless brome” (1 : 1) by 2.2–7.6, or 2.2–13.1%. Awnless brome in mixtures is more competitive than galega. An increase in the seeding rate of awnless brome from 3.0 to 6.0 million germinating seeds/ha in the herbage of galega increased the yield by 0.9–1.37 t/ha. The yield of dry mass of mixtures sown at the same time was higher than mixtures with awnless brome planted between rows of galega with spacing of 15 cm by 2%, and with row spacing of 30 cm by 10%.

The results of field and laboratory research for 2015–2017 are presented and analyzed on the cultivation of traditional and uncommon poaceous crops. Recognized varieties of barley, oats, and millet were studied in single-crop sowings and intercropped with a high-protein cabbage crop – oilseed radish. The research was conducted on meadow chernozem mealy-carbonate soil in the forest-steppe zone of Trans-Baikal Territory. Agricultural technology used for fodder crop cultivation was common for this area. The objects of the research were the following varieties: barley Anna, oats Metis, millet Bystroe, oilseed radish Tambovchanka. The experimental work was carried out in accordance with the generally accepted guidelines for field experiments. Poaceous crops and oilseed radish were assessed in terms of their adaptability to growing conditions and their economically valuable characteristics that ensure sustainable production of high-energy feed. In multi-crop agrocenoses of poaceous crops and oilseed radish, the yield increased and the quality of feed raw material improved. The best results of multi-crop sowings were achieved by oats and millet intercropped with oilseed radish. The yield of green mass was 38.8-39.7 t/ha, dry matter content – 4.88-4.90 t/ha, digestible protein – 810820 kg/ha, and gross energy – 46.3-52.2 GJ/ha with availability of digestible protein – 180-186 g per one feed unit. Multi-crop sowings of oats and millet with radish oilseed are more productive than single-crop poaceous agrocenoses in feed units by 1.5-1.7 times, digestible protein by 2.9-3.3 times, gross energy by 1.2-1.6 times, with 10.5-10.7 MJ of exchangeable energy in one kilogram of dry matter.

The results of research into rice sown for grain (2017–2018) are presented. The effectiveness of Concord fungicide (active ingredients tebuconazole, 125 g/l; triadimefon, 100 g/l) against rice Pyricularia was studied. The experiment was conducted in the conditions of the greenhouse experiment in the Primorsky Territory. Artificial inoculation of plants was carried out in the phase of 4–5 leaves with a suspension of conidia of the fungus Pyricularia oryzae Broomeet Cavara (concentration of 100 thousand in 1 ml). The test results were compared with the action of the preparation Favorit (active ingredients tebuconazole, 125 g/l; triadimefon, 100 g/l). Concord fungicide was used once on the next day after inoculation at a normal rate of 0.75; 1.0 and 1.25 l/ha. Under the influence of the preparation, the damage to rice plants decreased by 57.5% (0.75 l/ ha); 70.0 (1.0) and 69.5% (1.25 l/ ha) compared to the control. The use of fungicide contributed to an increase in plant growth by 7.6– 13.3 cm, and panicle length by 1.4–2.9 cm, and had a positive effect on the number of grains and the weight of grains in an ear. With the action of Concord, the mass of 1000 grains increased by 1.38 (0.75 l/ha); 2.14 (1.0) and 3.03 g (1.25 l/ha) compared to the control. The positive effect of fungicidal treatments of rice crops led to obtaining an additional grain yield. Concord does not show a phytotoxic effect and does not have a retardant effect on rice plants. The maximum indicators of biological efficiency were obtained with the use of the preparation at a flow rate of 1.0 and 1.25 l/ha. In agro-climatic conditions of the south of the Far East, Concord fungicide proved to be effective for protecting rice vegetating plants from Pyricularia.

The results of studying resistance of mid-ripening spring wheat cultivars to root rot in the forest-steppe zone of Irkutsk region are presented. The study was conducted in a two-factor field experiment. Factor A – mid-ripening spring wheat cultivars: Tulunskaya 11 (control), Zoryana, Маrsianka, Stolypinka (new cultivars). Factor B – seeding dates: May 10, 20, 30, preceded by fallow. The experimental plot area was 70.0 m². The experiment was repeated three times. Plot arrangement was randomized. Root rot prevalence was determined during the tillering phase of the crop. In 2018, the sowing dates did not affect the disease due to the long spring-summer drought (May-June) and a higher average daily temperature compared to long-term average values. In arid and cold conditions of May 2019, with the late sowing period (May 30), root rot prevalence was significantly lower than when sowing on May 10 and 20. In 2019, a higher level of the disease was registered than in 2018 by 14.3%. Significant differences in root rot prevalence in both years of research were noted between the control cultivar Tulunskaya 11 and the new cultivars of spring wheat Zoryana and Stolypinka. In the tillering phase of the latter two, disease indicators were lower by 5.6% and 10.5% in 2018, and by 8.8% and 7.9% in 2019, respectively. Маrsianka cultivar was at the control level for this indicator. The best cultivar under study was Stolypinka, which was not only less affected by root rot, but also gave a statistically significant yield increase of 0.16 t/ ha in 2018 and 0.22 t/ha in 2019.

The development of the nutriculture medium composition and the optimal concentrations of its constituent components to increase the bacteriocin-like activity of the strain Bacillus thuringiensis ssp. Dakota are presented. The study was carried out using a multifactor experiment with further processing of statistical data in order to optimize the basic nutriculture medium and maximize the activity of the target product. Sources of nitrogen (peptone and yeast extract) and carbon (glycerin and glucose) were used as optimization factors. The control growth medium was medium "A", traditionally used for the cultivation of bacteria of the genus Bacillus. The degree of impact of the studied factors on the effective feature was determined using the model of multiple linear regression of the first order, whereby the optimal ratio of the components was calculated on the basis of the quadratic model. The ability of the Bacillus thuringiensis ssp. dakota strain to produce a bacteriocin-like substance (BLIS) was revealed. The dependence of BLIS synthesis on the cultivation medium was established: on the carbohydrate-free medium, the antimicrobial activity of BLIS was 1.5 times lower than that on the medium containing glucose and glycerin. To obtain maximum BLIS activity, the carbohydrate medium was optimized using a multifactor experiment performed by the method of orthogonal Latin rectangles. Mathematical models of linear regression of the first and second order were constructed depending on the concentration of nutrient medium components. The optimal concentration of the components was determined on the basis of a second-order regression model that takes into account the effects of the interaction of factors and the nonlinearity of the process. As a result of optimization of the nutrient medium, the quantitative composition of the components of the culture medium was determined: peptone – 9 g/l; yeast extract – 2.6; glycerol – 5.6 g/l, on which the antimicrobial activity of BLIS increased by 60% compared with the activity on the initial medium. It was shown that the synthesis of BLIS, unlike the synthesis of delta-endotoxin, is not regulated by catabolite repression of carbon.

The materials of the long-term (2008–2018) research into the reproductive function of cattle of the black-and-white breed of Baikal type in Irkutsk region are presented. The influence of the age at the first insemination and live weight on cows’ milk productivity, lifelong productivity and productive longevity was studied. The experiment was conducted on the basis of materials from the breeder-farm for breeding cattle of Baikal type on the groups of cows of different ages: up to 14–20 months and older. Cows inseminated at 16 months (7917 kg) had the best milk yield in the first lactation. The largest milk yield was obtained from inseminated cows with live weight of 401-410 kg. Milk production of these heifers was 7902 kg in the first lactation, 8792 kg – in the second and 8710 kg – in the third. It was revealed that age of cows and their live weight at the first successful insemination had a positive effect on the lifelong productivity and productive longevity of cows. Cows whose age at the first successful insemination was 15 or 16 months had a longer duration of productive use (productive life span of animals was 2561–2558 days, respectively). The highest lifelong productivity (34379–34585 kg) was obtained from the cows of this group. The economic efficiency of lifelong milk production was determined depending on the age of the first insemination. The highest lifelong milk productivity was obtained from cows, which were first inseminated at the age of 15–16 months. The largest revenue from sales of additional products was also received from the cows of this group (366,058–370,480 roubles per head). The results obtained allow to develop effective methods for increasing reproductive capacity of cattle.

The role of line breeding in fine-wool sheep husbandry is shown. Productivity indicators of fine-wool sheep of Transbaikal breed of Khangil type, in the conditions of Trans-Baikal Territory are presented. Four inbred lines were created in the Khangil type of Transbaikal breed, which are distinguished by increased indicators of wool and meat productivity, as well as high wool indicators. These are lines No 616, 8351, 8099, 8349. The positive effect of the new lines on the improvement of productive qualities in the herd of fine-wool sheep of Transbaikal breed of Khangil type was revealed. Line-bred rams exceeded their peers in live weight by 0.5–3.5%, amount of washed wool shorn – 7.2–23.8% (p ˂ 0.01), yield of washed wool – 2.2–6.5 abs.%, wool length – 1.0–8.0%, wool coefficient – 1.7–11.5 g per 1 kg of live weight. Moreover, animals of line No 8351 differ from individuals of other lines in the increased density of wool fibers and significantly finer wool (p ˂ 0.05), corresponding to the 64th quality. Lines No 8099 and 8349 are represented by large individuals with high indicators of live weight and wool productivity, lines No 616 and 8351 are characterized by an increased amount of wool shorn combined with good growth and development indicators. Line-bred ewes exceed the breed standard in live weight by 12.5–24.3%, and the amount of shorn washed wool by 33.8– 40.7%. The length of hair was 9.3–9.6 cm, the proportion of animals with fine wool of 64th quality was 80.1–86.0%. The lines are maintained by selection of ewes both related and unrelated to the ram (line extension) that meet the requirements of the desired type and characteristics of the line.

The results of introducing silver nanocomposite based on zeolite and as part of Argovit preparation into the diet of poultry are presented. The experiment was carried out on quails of the Japanese breed during the periods of bird rearing (60 days) and productive use of laying quails (95 days). For the research, three groups were formed from quails aged one day (one control and two experimental) of 50 heads each. The quails were kept on a test farm in Novosibirsk Region in cell batteries subject to the required microclimate conditions. All groups received feed (the main diet), tailored to the age and physiological characteristics of quails. A silver nanocomposite based on zeolite and as part of Argovit preparation at a dose of 40 μg/kg of feed (on pure element) was additionally introduced into the feed for the birds of the experimental groups for 21 days. The effect of the supplements used was studied by the following parameters: survival rate of quail chicks, their growth intensity, feed efficiency ratio, indicators of meat and egg productivity, and quality of hatching eggs. The chemical composition of the feed, quail meat and eggs obtained from laying quails was studied in a biochemical laboratory using generally accepted methods of zootechnical analysis. When feeding experimental birds on silver nanocomposite based on zeolite and as part of Argovit preparation, the survival rate of quails increased by 3.0–4.0%, the average daily gain in live weight increased by 6.48– 7.35%, and feed consumption per unit of the produce decreased by 13.14–16.62%. The egg production of laying quails increased by 6.00–7.45%, the yield of egg mass – by 6.02–7.89%, and the yield of hatching eggs – by 3.33–11.7%. The highest indicators of meat and egg productivity and feed efficiency were obtained in the first experimental group that consumed zeolite-based nanosilver. The economic effect in the experimental groups increased by 13.76-17.26% compared to the control group.

Research has been conducted to evaluate the effect of antibiotics and silver nanoparticles in combination with antibiotics on the change in antibiotic sensitivity to antibacterial drugs of E. coli ATCC 25922 reference strain and its isolate. Nanoparticles obtained by electron beam treatment of aqueous solution containing water-soluble stabilizing polymer and water-soluble silver salt were used in the experiment. During the treatment a beam of accelerated electrons obtained on the installation of a linear accelerator of the ILU-10 type passed through a solution with a working dose of 5–30 kGy ranging in size from 20 to 60 nm. Sensitivity of microorganisms of E. coli ATCC 25922 reference strain and its isolate obtained from cow endometritis to antibacterial substances and their combinations was determined from dilution with a minimum bacteriostatic concentration. The dilution in the amount of 0.2 ml was added to meat-and-peptone agar and the antibiotic sensitivity of microorganisms was determined by the disk diffusion method. Sensitivity to 24 types of antibacterial drugs was tested. Cultivation of E. coli ATCC 25922 with AgNPs in combination with one of the antibiotics (azitronite, amoxicillin, enroflox, ceftiofur, tylosin, cobactan, oxytetracycline) contributed to an increase in the number of drugs (from 14.3 to 57.1%), to which the microorganism was sensitive. Cultivation of the E. coli isolate with 5 (62.5%) of the studied antibiotics led to an increase in resistance from 1 (5.5%) to 3 (16.7%) antibacterial agents. AgNPs in combination with antibiotics azitronite, amoxicillin, enroflox, ceftiofur, tylosin, cobactan, gentamicin, oxytetracycline contributed to a decrease in the resistance of E. coli ATCC 25922 (from 15.4 to 46.1%) and E. coli field isolate (from 16.7 to 37.7%) to antibacterial drugs. The pronounced ability of AgNPs to increase antibiotic sensitivity was established. This was confirmed by the joint cultivation of antibiotics and AgNPs with E. coli ATCC 25922 and field isolate of E. coli, causing an increase in sensitivity and high sensitivity to antibacterial drugs, which was previously absent. The study confirmed the results of research on the ability of nanoparticles of metals of the transition group to affect the sensitivity of microorganisms to antibacterial agents and to restore it.

Research has been conducted to improve the efficiency of agricultural production by choosing technology and technical equipment based on a mathematical model, taking into account the peculiarities of location and production conditions of a farm. The limiting factors of the development of grain production are highlighted such as moisture content and the sum of temperatures during the growing season, frost-free period, etc. Basic soil tillage technologies that minimize the impact of limiting factors on the yield are considered. A generalized block diagramme of the selection process of technologies and technical means for the crop cultivation is presented. Constraints are formed that affect the choice of agricultural technology such as soil and climatic conditions, phytosanitary conditions, crop rotation, availability of seeds and  equipment,  etc.  Optimization  criteria have been substantiated that allow to choose technologies and technical means, ensuring cost reduction, energy saving and labor saving while following the specified agrotechnical deadlines of technological operations. A mathematical model has been developed with optimality criteria: consumption of fuels and lubricants, the number of machine operators and production cost. The model includes the following restrictions: the agroclimatic location of the farm, personnel potential, and fulfilment of a given amount of work. The model allows to evaluate agricultural technology and technical means according to the following parameters: the minimum amount of direct costs, the minimum consumption of fuel and lubricants and the necessary number of machine operators for the implementation of agricultural technology. This model will become the basis of the software, which will be used to test the results and data obtained on a specific farm. The use of this software will increase the efficiency of agricultural production by making informed management decisions for agricultural producers in the selection and implementation of technologies.

The results of testing new Agrostab computer program “Indicators of stability of agricultural crops varieties” based on long-term (2017–2019) field research data in Novosibirsk region are presented. The program implements modern methods for assessing the ecological plasticity of varieties and allows to evaluate the stability of genotypes by a set of phenotypic characters. The research material was common spring wheat varieties from the Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences (Novosibirskaya 15, Novosibirskaya 31, Sibirskaya 12), and collection forms of spring hexaploid triticale from the VIR world collection Lt-F6544-6 (k-3992), variety Ukro (k-3644) and Sears 57 × Ukro hybrid received as a result of breeding. The samples had a different ecological and geographical origin and belonged to different ripeness groups. Plants were grown organically without the use of fertilizers and pesticides. They were sown at different times after bare fallow in four repetitions. In the course of the experiment, the following genotype stability indicators were determined: environmental variance, coefficient of homeostaticity, weighted homeostacity index, steadiness of stability index, coefficient of multiplicativity, specific adaptive ability, superiority measure, ecovalence, regression to environmental index, non-parametric stability index. The necessity of using the complex value of the integrated selection index to calculate the parameters of plasticity and genotype stability is shown. Testing of the Agrostab program for breeding of spring triticale made it possible to determine the targeted vector for the selection of varieties in the agroclimatic conditions of Western Siberia and adaptive samples to be included in hybridization. The use of new models and methods of statistical data analysis to determine the environmental plasticity of varieties and hybrids will increase the efficiency of the breeding process.

The results of the study of hematological and biochemical blood parameters of Altai-Sayan breed of marals are presented. Blood parameters of 5–6 year-old stag marals brought from the Altai Republic in 2014–2015 and currently bred in the Republic of Tuva were studied. Content of total protein in blood was lower than the established standard indicators for maral blood by 12.8%, albumin by 51.5, betaglobulin by 72.4, and cholesterol by 59.5%. The following indicators exceeded the standard: number of leukocytes – by 40.4%, alpha-globulins – by 21.0%, gamma-globulins – 2.1 times, AcAt – by 6.8%, glucose – by 16.4%. The average IgA content in the blood of the studied animals was 0.022 mg/ml, IgG – 0.039, IgM – 0.020 mg/ml. A weak negative correlation was found between the content of IgG and the number of leukocytes (r = –0.38), as well as an average positive correlation between the level of IgA and the concentration of urea in the blood (r = 0.47). In the study of the phagocytic system of stag marals of the Tuvan population, the values of phagocytic activity were established at the level of 25.4 ± 0.29, the phagocytic index – 4.33 ± 0.09, and the phagocytic number – 1.03 ± 0.03. The revealed interconnections of the hematological, biochemical and immunological parameters of blood of stag marals brought from the Altai Republic and kept in the Republic of Tuva differ both in strength and in direction. Average negative correlations amounted to 41.9% of the total, average positive – 38.7, high positive – 12.9, high negative – 6.5%. Differences in the morphological and immunobiochemical composition of the blood of marals bred in the conditions of the Republic of Tuva from standard indicators are the result of optimal adaptation to the living conditions.