The authors studied sorption properties of the alluvial light-humus soil (Republic of Buryatia) relative to lead under static conditions. The paper presents determined parameters and kinetics of lead sorption from aqueous solutions of lead nitrate by soil. A series of soil suspensions were used in the experiment, from which aliquots were taken at fixed intervals (30-1440 minutes) to determine the residual concentration of lead ions with atomic emission spectroscopy. The experimental data were processed using the Langmur and Freundlich equations. Such sorption parameters as A_max, K_L, K_p 1/n, R², ∆G, S of specific surface were calculated relative to lead ions. It is shown that the A_max of the studied soil is 100.6 mmol • kg^-1 in the studied concentration range. It has been established that about 99% of lead ions are absorbed by the soil in the first 3 hours and the adsorption equilibrium in the lead-soil system is mainly reached in 3-24 hours, depending on the initial lead concentration. The kinetics of lead ion sorption by the soil under study is satisfactorily described by a pseudo-second order model. This leads to a conclusion that the sorption of lead ions is limited by the stage of chemical reaction.

Currently, there are no scientifically approved resource-saving technologies for growing plum seedlings in Non-Chernozem nurseries. Therefore, the study was aimed at determining the effect of variable soil moisture supply on the growth and development of plum seedlings. Based on this parameter, a rational mosture regime of Non-Chernozem nurseries can be developed. Field studies were conducted on the territory of a study experimental farm and the fruit-growing laboratory “Mi-churinsky Garden” at Russian Timiryazev State Agrarian University. Two-factor experiment to study the effect of different mosture regimes on the development of plum seedlings of two varieties grafted on plum seedling rootstock was laid in the spring of 2016. A long-lasting drip line was used for irrigation. Soil moisture was monitored using tensiometers graduated on the basis of the thermostat-weight data. The irrigation regime (irrigation frequency and rate) was selected based on the actual soil moisture, which is associated with such climatic indicators as air temperature and precipitation rate. The maximum irrigation rates are typical for the majority of moistened options, but it should be noted that the irrigation rate in 2017 was greater than that of 2016. The experimental results have shown that plum seedlings grown under conditions of insufficient and uneven moisture supply are characterized by the lowest biometric indicators. The biometric indicators of plants prove that the most optimal is the drip irrigation regime with maintaining soil moisture in the range of80-100% HB.

The paper reports on test results based on the deterministic estimates obtained using a PF + PE model (production frontier plus partial equilibrium model) in 80 regional markets of Russia. Two interrelated null hypotheses have been tested regarding to the impact of the adoption of grain export duties in Russia. The first hypothesis is that these duties do not improve the availability of the dominant food products to the population. It has been tested for Russia as a whole as well as for its 80 federal subjects. The second is that these duties do not stimulate the production of the main animal products, which is tested for Russia as a whole and for 78 federal subjects. The tests are applied retrospectively to the period from 2011 to 2015. The study disapproved the null hypotheses. The first hypothesis was rejected for 61 federal subjects of 80 but not for Russia as a whole, due to reduced consumption of milk products resulting from the duty introduction. The second hypothesis was rejected both for Russia as a whole and for 12 federal subjects of 78 tested ones. The export duties for grain provide either weak or contradictive (in some regions) advantages to the growth of animal production and cause incomparable damage to grain production. Under such duties, food consumption in Russia can be increased wholly due to the food products made of grain. Additional estimated inflow in the federal budget resulting from the considered duty is less than agricultural losses (including those of trade agents engaged in farm produce wholeselling and exporting). Due to this reason, thy present study supports the recent decision of the Government of the Russian Federation to postpone the implementation of the grain export duty until July 1, 2021. The results raise the question about legal provisions for zero grain export duties and establishing permanent criteria of extraordinary situations that would allow temporary introduction of the grain export duty.

The paper presents some material on the extensive use of the Holstein breed in the Syrian Arab Republic to improve local breeds. The results indicate a positive effect of Holstein crossing with indigenous breeds of Shami and Okshi. Milk productivity of crossbred animals has doubled. Crossbred cows of different genotypes and generations have a greater live weight at birth than local breeds. Crossbred cows from crossing the Holstein breed and the Shami breed feature a pregnancy period of 284 days, and crosses of the Holstein breed and the Okshi breed are inferior to them and their duration of embryogenesis is shorter by 4 days. When assessing the relationship of the dry period duration, the following results were found: in the purebred Holstein breed, the relationship in the mother-daughter groups was weak and negative r = -0.131. In cows of the Shami and Okshi breeds and their crosses with the Holstein breed a positive low relationship was observed: r = 0.032, r = of 0.085, r = 0.06. The study of reproductive functions in cows of different genotypes found that significantly small age of one insemination in Holstein cows was 18.0 months (540 days), while the latest one was observed in cows of the Okshi breed - 22 months (660 days), the difference being 4 months. Indicators of milk yield vary in crossbred cows in contrast to the original local breeds, so in crossbred cows from Holstein producers and cows of the Shami breed milk yield was 4426 kg with a duration of embryogenesis from 276 days to 283 days, which is lower than that of Holstein cows by 2700 kg, but higher than that of the Shami breed by 2708 kg. Positive relationship has been determined between the live weight of cows at birth, the average indicator of the Okshi breed r = 0.340. The study has revealed positive correlation in the duration of the calving interval in of mother and daughter cows: r = 0.341.

The paper presents the newly developed Sunlin oilseed flax variety possessing valuable biological and economically useful properties inherent in flax as a plant. The composition of its oil is adapted for long-term storage. Over a period between 2017 and 2019, a technology has been developed for cultivating this type of flax in the soil and climatic conditions of the Non-Chernozem zone of Russia, which allows obtaining oilseeds with high quality indicators. For 2017-2019, the average yield of the Sunlin variety of about 16.5-18.8 kg was achieved in the Ryazan region. Higher yields were provided by crops with a high level of mineral nutrition (N90-120P60K60) and seeding rates (8-10 million units/ha), at the earliest possible sowing period. It has been established that in the conditions of the Ryazan region, a higher yield of flax of the Sunlin oilseed variety is achieved at the first sowing period, i.e. the first decade of May. The sowing period had a significant effect on the water and temperature regimes of the development of the Sunlin flax variety throughout the growing season. The conducted studies have led to a conclusion on the accumulation of fatty acids in flax seeds at different stages of maturation. Based on the results, the authors have presented the dynamics of changes in the chemical composition of seeds, depending on the phase of growth. The analysis of flax seeds at different stages of maturation showed the predominance of initially saturated and oleic acids, with later formation of linoleic and linolenic acids. On average, in the phase of full ripeness, the Sunlin seeds contain the following valuable unsaturated acids: oleic - 18.3%, linoleic - 65.9%, and linolenic - 8.0%. The highest oil content was observed in fully ripenedseeds. On average, the oil content of the Sanlin variety amounted to 42.5%.

The author studied gender ratios in three populations of a valuable dioecious plant - cloudberry grown in Kandalaksha district of Murmansk region. The paper describes the microstructure of flowering shoots in female and male cloudberries with the purpose of revealing new features of sexual dimorphism. Male individuals predominated in all of the studied populations. The largest percentage of female individuals was found on a forest site, the smallest percentage - in a boggy forest near a stream. The highest density and, accordingly, the largest number of individuals per square meter were found on a hummock-ridge bog. The anatomical structure of axes, leaves and sepals is similar in male and female plants. The difference is in the absence of mechanical tissue in peduncles in male forms. This fact can be explained by their short life unlike the peduncles of female individuals that need to hold the fruit for a long time. The obtained results have been compared with the data provided in the reference sources.

In recent years, the world population of dairy goats has grown. Advanced farms have observed a significant increase in the productivity of dairy goats up to 1600 kg of milk on average in the herd. This is ensured by the development of industrial technology, new methods and techniques of feeding, herd reproduction and rearing. Robotized complexes for feed preparation and distribution, etc. are being introduced on farms. The range of scientific achievements in dairy goat breeding includes the technology of prolonged lactation from 600 to 1500 days without tupping. In the UK, a new breed of Yorkshire milk goats has been developed with an average productivity of 1600 kg of milk and prolonged lactation for more than 600 days. Industrial goat breeding is also developing in Russia and the CIS countries. Animal productivity on the best farms is comparable to the average European indicators of 900-1000 kg of milk per lactation. The most common goat breeds such as Zaanen, Alpine, Toggenburg, and Nubian are imported to our country:

The paper presents the approbation results of the program “Assessment of the breeding value of hogs using the BLUP method” developed by All-Russian Research Institute of Pedigree Breeding (VNIIplem) in cooperation with LLC “Selikom” (Ryazan). The authors show some factors affecting the breeding value of the animals and give the basic provisions of their genetic evaluation with the method of best linear undistorted prediction (BLUP). Comparative studies were carried out to check the accuracy of animal estimation using the BLUP method and the conventionally used method according to the “Procedure and conditions for the assessment of breeding pigs”. The study results confirmed the higher accuracy of the animal estimation using the BLUP method.