Sod-podzolic Sandy Loam Soil Research Articles

Productivity, quality and suitability for processing of various potato varieties when grown in the conditions of the Central region of the Russian Federation

Relevance. The study of the reaction of potato varieties, especially new ones, to the use of a complex of agrotechnical techniques, including foliar top dressing with water-soluble fertilizers, is an urgent task. For this purpose, 4 potato varieties of different ripeness groups (Red Scarlett, Nevsky, Golubizna, Grand) were studied in two regions of Russia using agrochemicals Agrovin Micro. Methods. The article presents experimental data on the study of biometric indicators, yield and quality of potatoes for non-root top dressing in conditions of leached chernozem and sod-podzolic sandy loam soils of the Central region of Russia. The objects of research were potato varieties of various ripeness groups. Foliar fertilization of plants with agrochemicals Agrovin Micro was carried out in the phases of germination, budding and 20 days after the last treatment in two consumption rates – 1.0 and 2.0 l / ha. Control – without processing (K) with background N90Р90К135.Results. On average, over the years of research, the best options for all varieties turned out to be options with the use of additional leaf treatment with an agrochemical at a maximum dose of 2 liters /ha. Due to three-fold foliar top dressing for the critical phases of potato plant growth, the greatest yield increases and maximum values of dry matter and starch content to the mineral background were obtained. In the conditions of the Tambov region, the increase in yield, depending on the variety, ranged from 24.2 to 59.3% or 6.0-10.5 /ha and in the conditions of the Moscow region – 3.3-28.9% or 1.2-7.1 t/ha. The most suitable for processing into fried potato products from the studied varieties turned out to be Red Scarlett and Grand. All other things being equal, the color index of crispy potatoes and fries on these varieties was higher than the Nevsky variety by 1.0-1.5 points.

Содержание валовых форм цинка, свинца и кадмия в дерново-подзолистых супесчаных почвах земель сельскохозяйственного назначения

Abstract. Purpose and objectives. The research is aimed at studying the peculiarities of the distribution of gross forms of zinc, mumps, cadmium according to the soil profile of sod-podzolic sandy loam soils of agricultural lands of the Ryazan region and determining the current regional background. Methodology and methods. To solve the tasks set, pits with a depth of 1.5 m were laid in different regions of the region, the depth and structural features of the soil layer and the effect on the migration conditions of the studied elements were analyzed. Based on the results of determining the content of the studied elements in the soil at intervals of 0.1–0.2 m to the maternal, the calculation of background concentrations was performed. A comparative analysis of the proposed background values with well-known values of world and domestic researchers has been carried out. The scientific novelty of the conducted research lies in the fact that the proposed background values are modern and calculated directly for the sod-podzolic sandy loam soil of the Ryazan region. Results. The structure of soil profiles of sod-podzolic sandy loam soil at a depth of 110–120 cm has the following form: O – A – EL – ELBt – Bt – BtC – C. At the same time, noticeable geochemical barriers delaying the migration of heavy metals are noted in the horizon A and Bt. The obtained values of the studied elements were in the concentration ranges for Zn (5.4–12.8 mg/kg), Pb (2.1–7.4 mg/kg), Cd (0.031-0.081 mg/kg). Background concentrations are proposed: Zn – 8.3 mg/kg, Pb – 4.2 mg/kg, Cd – 0.053 mg/kg, which differ from the well-known values of world and domestic researchers presented in a comparative analysis and give a modern idea of the regional background content of gross forms of zinc, lead and cadmium in sod-podzolic sandy loam soils Ryazan region.

Assessment of the Modifying Effect of Zinc and Copper on Toxic Stress of Barley Plants Caused by Cadmium

In a vegetation experiment on sod-podzolic sandy loam soil with Cd2+ addition at doses of 25 and 45 mg/kg, we studied how the response of barley plants to the toxic effects of cadmium changes if various amounts of heavy metals (HM) with the functions of trace elements were introduced together with it, using the example of zinc and copper. In addition, several variants were laid, in which copper and zinc were also introduced along with cadmium. Thus, doses and combinations of metals were used in the experiment: Cd45, Cd25Cu50, Cd25Cu100, Cd25Cu100, Cd25Cu200, Cd45Cu50, Cd45Cu100, Cd45Cu200, Cd45Zn50, Cd45Zn100, Cd45Zn150. Morphometric parameters (appearance, height of plants, their biomass and leaf area), biochemical parameters (accumulation of MDA, total antioxidants and crude protein), crop structure (straw weight, grain weight, 1000 grain weight) were evaluated in experimental plants. In addition, the gross content of HM and other elements in the soil and their transition to the soil solution were analyzed. It is shown that the introduction of cadmium alone led to a significant inhibition of the growth and development of barley plants. At the same time, the combined addition of HM trace elements with cadmium significantly modified the effect of cadmium. Zinc contributed to a decrease in the toxic effects of cadmium, and the intensity of this effect increased as the concentration of zinc increased, and the toxic effects of this HM at the doses considered had not yet manifested themselves. Copper, as a more toxic element, showed its stimulating effect at lower doses than zinc, and at higher doses, the development of acute stress caused by the combined toxic effects of 2 HM was observed. This is true for a dose of cadmium of 45 mg/kg, with a lower dose of cadmium (25 mg/kg), copper had a greater stimulating effect. The considered effects were primarily noted when evaluating morphometric indicators and productivity. Based on the biochemical parameters, it was not possible to draw clear conclusions about how the addition of zinc and copper changed the effects of cadmium. Apparently, it was more appropriate to use other biochemical parameters to assess stress effects. It was noted that the introduction of trace elements generally contributed to a reduction in the accumulation of cadmium in the aboveground biomass of barley plants, however, the addition of zinc led to an increased transition of cadmium into straw, but not into grain.

Effect of fertilizers and meliorants on the value of soil acidity of sod-podzolic light loamy soil, yield and chemical composition of the green mass of spring rapeseed (according to laboratory and vegetation experience)

Under controlled conditions of laboratory vegetation experience based on very strongly acidic sod-podzolic sandy loam soil, a comparative study of the fertilizing value and reclamation properties of complex mineral fertilizers (azofoska andAPAVIVA) and meliorants of a carbonate nature was carried out: conversion chalk (CC), gravel screening (GS), dolomite (DM) and dolomitized (DIM) limestone flour, as well as silicate nature–blast furnace slag (BFS) and hydroxide nature–Mg(OH)2.Culture–spring rape of theLexus variety.It was shown that the reclamation effect obtained as a result of the use ofBFSand meliorants of a carbonate nature differed little from each other and after 45 days of plant cultivation were insignificant.Magnesium hydroxide did not have a reclamation effect.The yield data of the vegetative mass of rapeseed after harvesting are given.It is shown that the chemical composition of meliorants had a significant effect on the formation of the elemental composition of plants.

Восстановление плодородия малопродуктивных дерново-подзолистых почв, вновь вводимых в сельскохозяйственный оборот

The purpose of research is to develop agro-reclamation measures to restore the fertility of low-productive sod-podzolic sandy loam soils for the conditions of the southern part of the Non-Chernozem Zone of Russia. Objectives: to conduct a comparative assessment of the impact of granular fertilizer based on turkey droppings and a liquid-phase biological product (LPBP) on increasing soil fertility, phenological characteristics of plants, crop yields and their quality. Six variants of the field experiment were developed: control variant (without fertilizers); granular fertilizer based on turkey droppings at a dose of 15 t/ha; granular fertilizer based on turkey manure at a dose of 15 t/ha together with pre-sowing seed treatment with 1 % LPBP; pre-sowing seed treatment with 1 % LPBP; granular fertilizer based on turkey droppings at a dose of 30 t/ha. The application of organic ameliorant and pre-sowing treatment of seeds with a biological pre¬paration help to improve the agrochemical parameters of the soil, and, as a result, a higher yield of perennial grasses. The best option is option G30, where the yield was 48.3 t/ha of green mass of grass in total for 2 cuttings, which is 33.8 % more than the control option. In the G15 and G15 LPBP options, the harvest was practically not inferior and exceeded the control option by 30.5 and 24.4 %, respectively, soil fertility indicators improved: soil acidity decreased to 4.8–5.0 (pHsol) and 5.4–5.6 (pHwod), an increase in organic matter by 33.9 %, the content of mobile phosphorus and mobile potassium, and the concentration of total nitrogen increased significantly.

Изучение защитных свойств дерново-подзолистой супесчаной почвы при применении осадков сточных вод

The article considers the protective properties of sod-podzolic sandy loam soil when using sewage sludge. It is proved that there is an increase in the coefficient of protective properties of the soil when using sewage sludge in doses up to 10 t/ha. With an increase in the precipitation dose, the protective properties of the soil decrease, which is associated with the sorption capacity of the soil to the metals in question (zinc and cadmium). When wastewater precipitation is applied in doses of more than 10 t/ha, the protective properties of the soil weaken and the number of mobile forms of zinc and cadmium begins to increase. Keywords: HEAVY METALS, SEWAGE SLUDGE, ZINC, CADMIUM, COEFFICIENT OF SOIL PROTECTIVE PROPERTIES

Dynamics of pH<sub>KCl</sub> of calcified sod-podzolic sandy loam soil by meliorants of various chemical nature

The possibility of accelerating the reaction of meliorant-freshly calcified soil in a solution of 1 n. KCl is shown. Changes in the pH value during 20 days of soil-solution interaction were traced. Differences in the reaction rate have been established when using ameliorants of various chemical nature for liming. It was revealed that the reclamation effect when using silicate materials in the experiment was less than that of carbonate. According to the effect achieved as a result of liming, all meliorants used in the experiment can be arranged in the following descending order: dolomite flour (DF), crushed stone screening (CSS) conversion chalk (CC), dolomitized limestone flour (DLF) blast furnace slag (BFS) shale ash (SA). Empirical models of changes in the pHKCl value over the entire experimental interval have been developed for all lime fertilizers. Clustering of individual variants of the experiment, produced by various meliorants, according to their effect on the pHKCl index over the entire period of study was carried out.

ПРИМЕНЕНИЕ ОРГАНОМИНЕРАЛЬНОГО КОМПЛЕКСА ГУМИТОН ПРИ ВОЗДЕЛЫВАНИИ ОВСА НА ДЕРНОВО-ПОДЗОЛИСТОЙ ПОЧВЕ

Based on the data of a field experiment on sod-podzolic sandy loam soil in the Kaluga Region, it was shown that the use of the organo-mineral complex Gumiton had a positive effect on the biometric indicators of growth and development of oat plants, yield and quality of vegetative mass. When oats were treated with Gumiton in the boot-up phase, the vegetative mass yield increased by 13 %, in the earing phase - by 46 %, and with a double treatment of plants in both these phases - by 48 %. A single treatment with Gumiton in the boot-up phase did not lead to an increase in grain yield, but increased the straw mass by 21.5 % in relation to the control; when treated in the earing phase of oats, the grain yield increased by 17 %, and the straw mass - 23.5 %. Treatment of crops with Gumiton in the oat boot phase contributed to an increase in the ash content in grain by 12 %, double treatment – by 18 %. The content of crude protein in grain did not change either with a single application of Gumiton in different phases of plant development or with double spraying. The fiber content in grain increased with the use of Gumiton in the boot phase of oats by 21.5, at the panicle stage – by 13, and with double treatment – by 31 %. Double spraying of oat crops with Gumiton led to a 17 % decrease in the fat content in the grain.

Features of narrow-leaved lupin (Lupinus angustifolius) development and productivity in the application of micronutrients in the conditions of the Central Non-Chernozem zone of Russia

The results of three years of field research in conditions of low-fertile sod-podzolic sandy loam soil of the Kaluga region on the study of growth, development, and seed productivity of narrow-leaved lupin during foliar fertilization of plants with BorSTART, MicroStim-Marganets, and Novalon 19-19-19+2MgO+ME fertilizers are presented. The use of micronutrients increased the height of narrow-leaved lupin plants, starting from the flowering phase and the leaf area from the budding phase to the end of the vegetation of plants. The largest leaf area in the flowering phase was found in options with the treatment of plants with micro-fertilizers BorStart – 480.2 cm2/plant and Microstim Marganets – 475.3cm2/plant. The treatment of plants with micronutrients exceeded the control variant by weight of the aboveground mass in the phase of glaucous pods by 8.4–11.6%. The best results were obtained when treating plants with boric micro-fertilization (BorStart). Micro-fertilizers increased the yield of narrow-leaved lupin seeds in an average of 3 years from 0.16 to 0.38 t/ha compared with the control. The highest seed yield was when processing plants with chelated forms of micro-fertilizers – Novalon and MicroStim Marganets. The use of micro-fertilizers led to an increase in the content of crude ash and crude protein in lupin seeds.

Исследование интегральной токсичности почвы, загрязнённой нефтепродуктами

The effect of contamination with technical waste oil on the integral toxicity of sod-podzolic sandy loam soil under field experiment conditions was studied. The integral toxicity of the soil aqueous extract was determined using the «Ecolum» bacterial test, which is a luminescent gene-engineered Escherichia coli. Control soil samples show acceptable levels of toxicity. Soils contaminated with 10 or 20 g/kg doses of petroleum products are moderately toxic. The dose of 30 g/kg makes the soil highly toxic for luminescent microorganisms. The hydrocarbon composition of technical waste oil was determined using spectral coefficients obtained by infrared spectrometry. High content – 6.73% – of aromatic hydrocarbons (the most toxic fraction) was revealed. Correlation analysis between the soil toxicity index, the content of oil products, heavy metals (Co, Ni, Cu, Zn, Pb) and the pH of the soil aqueous extract showed a very strong positive correlation between toxicity and zinc content (r = 0.88) and oil products content (r = 0.83) in the soil, as well as a high negative correlation on soil pH (r = –0.61). The phytomass of plants growing on contaminated sites was determined. A very high inverse correlation (r = –0.82) between the content of oil hydrocarbons in the soil and phytomass confirms that soil contamination with an increased dose of oil products reduces the biomass of the aboveground part of plants. A general tendency to displacement of monocots and their replacement by dicots was observed for polluted soils.

Effect of «Quantum» system preparations on biometric parameters of potato plants

The article presents the results of research on the influence of different preparations of the «Quantum» system on the biometric parameters of potato plants of the medium-early variety «Zhytnytsia» and the medium-ripening variety «Melaniya». The purpose of the research is to develop new and improve existing agrotechnical measures for growing new potato varieties on sod-podzolic sandy loam soils of Ukrainian Polissya. It has been experimentally proven that the application of a complex of agrotechnical measures has a positive effect on the biometric indicators of potato plants development during the growing season. New potato varieties «Zhytnytsia» and «Melaniya» responded positively to fertiliser application, their rates and methods. According to the studies conducted in 2021–2022, both «Zhytnytsia» and «Melaniya» varieties distinguished 2 variants, the 4th and 6th, where N90P60K90 (locally) + «Quantum Seamin» (0,5 l/t) + Prolonged nitrogen (leaf – budding, flowering, after flowering) and N90P60K90 (locally) + «Quantum Diafan 3-18-18» (2 l/t) + Prolonged nitrogen (leaf – budding, flowering, after flowering) were applied. In 2021 in the varieties «Zhytnytsia» and «Melaniya» on average the period from planting to full germination was 44 days, from planting to budding – 58 days, from planting to flowering – 64 days. The period from planting to tops dieback in 1, 3 and 5 variants of «Zhytnytsia» variety was 100 days, and in 2, 4 and 6 variants – 110 days. Accordingly, in «Melaniya» variety these figures were 110 and 120 days. The highest density was found in variants 4 and 6, respectively, 49.3 and 47.5 thousand bushes/ha. In the same variants the field germination rate was 92.5 % and 89.1 %; the number of stems was 3.9 (401.7 thousand pcs/ha) and 3.5 (367.5 thousand pcs/ha) per plant respectively; plant height was 77.0 and 73.0 cm; leaf surface area was 229.2 and 194.3 cm² respectively. Similar results were obtained for the «Melaniya» variety. The same variants had a longer growing season due to the use of prolonged nitrogen, which had a good effect on the yield. Thus, after analysing these indicators, we can conclude that the best options for varieties «Zhytnytsia» and «Melaniya» are variants 4 and 6. Key words: potato, budding, flowering, tops dieback, density, height, leaf surface area, preparations.

Translocation of Calcium into Spring Rape Plants from Sod-Podzolic Sandy Loam Soil Reclaimed with Conversion Chalk in a Wide Range of Doses. Comparison of Data Preparation Techniques for Building Empirical Models

In a 24-year vegetation precision experiment based on acidic sod-podzolic sandy loam soil reclaimed with conversion chalk (CC) in a wide dose range, the effect of liming on the content of calcium available to plants in the soil and its translocation into rapeseed tissue was established. The results showed that rapeseed is an ecologically plastic plant species. An increase in the amount of chalk introduced from 0.1 to 3 full doses calculated by hydrolytic acidity led to an increase in the Ca concentration in rapeseed in the liming year from 0.81 to 3.14%. Empirical dependences of calcium concentration in soil and plants on the dose of chalk application have been developed. 3 approaches to the analysis of experimental data describing the relationship of calcium content in the soil with its accumulation in plant tissues are considered. It is shown that artificial averaging of the data on the calcium content in the soil with the same dose of meliorant in individual repetitions led to loss of information, which was reflected in the statistical characteristics of the constructed empirical models.

Changes in crop rotation productivity and stability of agrocenoses with prolonged use of fertilizers

The article considers the results of many years of field experiment (1968-2018) conducted in the Central part of the Non-Chernozem zone of Russia (Vladimir region). The research was carried out during eleven rotations of the four-field grain crop rotation. The study shows the effect of use of organic and mineral fertilizers applied in various doses and combinations on crop rotation yield, fertility of sod-podzolic sandy loam soil. It was found that the organomineral fertilizer system (manure 10 t/ha + N50P25K60) provided stable crop rotation productivity (on average for eleven rotations) at the level of 39.9 c. e./ha, or 79.7 % higher than the control without fertilizers. The mineral fertilizer system at medium doses of fertilizers (N50P25K60) was at the level of the organomineral system. The organic system was inferior in efficiency to the mineral system, both at medium doses (manure 10 t/ha) and at elevated doses (manure 20 t/ha). At the same time, the long-term use of organic fertilizers provided an increase in the humus content, depending on the dose of litter manure, by 16-36 % compared to the initial values. The use of organic fertilizers led to the stabilization of the content of available forms of potassium in the soil at an average and elevated level, respectively. Stabilization of the content of mobile phosphorus in the soil at the level of average supply was noted in mineral, organomineral and organic fertilizer systems, respectively, with low and medium doses. When using increased doses of fertilizers, there is a further increase in the content of nutrients in the soil. Growing crops in crop rotation without the use of organic and mineral fertilizers gradually led to a decrease in yield. The use of fertilizers provided greater stability of crop yields over the years of the study compared to the variant without fertilizers. The soil in the variants with organic (manure 20 t/ha) and organomineral (manure 10 t/ha + N50P25K60) fertilizer systems was characterized by high values of the main physiological groups of microorganisms. The ratio of the number of amylolytic and proteolytic microorganisms was 1.1-1.2, that indicated a balance in the processes of mineralization of organic matter in the soil and its humification.

The content and composition of organic matter of sod-podzolic soil when applying fertilizer mixtures based on sewage sludge

Relevance. The organic matter of the soils of the Non-Chernozem zone requires additional sources of its replenishment, which can include sewage sludge (SS). The paper investigates the use of sewage sludge from Tver, introduced fresh into a mixture with additional organic substrates (sawdust, peat, straw) in the field crop rotation link.Methods. The experiment was carried out in the Tver region on sod-podzolic sandy loam soil in fourfold repetition. OSV was introduced as part of a total dose of a fertilizer mixture of 60 t/ha with additional organic substrates (sawdust, peat, straw) taken in different proportions (1:1, 1:2, 1:3) at the beginning of the experiment. The area of the experimental plot is 6 m2. Crops of the crop rotation link — mixture vetch and oat, winter rye, spring barley. The content of organic matter, its group and fractional composition were determined in soil samples according to the methods generally accepted in agrochemistry.Results. The introduction of SS together with additional substrates contributed to an increase in the amount of soil organic matter (1,38–1,5%) and its maintenance in the aftereffect at the level of 1,33–1,49%, in the control variant this indicator was 1,26% (the significance of differences p < 0,05). The studied fertilizers provided an increase in the share of GA-1 and a decrease in FA-1a. In comparison with the finished compost, fertilizer mixtures, in which the components were in equal proportions, were ahead of the comparison options in their effect. They also contributed to the highest increase in productivity of the crop rotation link among all the variants of the experiment (an increase in control — 61,1–68,2%). Compost provided an increase in productivity by only 37,9%.

Prospects for the use of Walnut and Poplar in agroforestry of Polissya and Forest-Steppe of Ukraine

Climate changes actualise the need for the transition of Ukraine’s agricultural business to agroforestry systems not only in the steppe but also in the northern regions of the country. The purpose of the study is to examine the features of creating protective stands of Walnut (Juglans regia L.) and Poplars (Populus × euramericana) in Polissya and in the Forest-Steppe of Ukraine. Experimental plantings of Walnut were created by one-year-old seedlings on sod-podzolic sandy loam soils of Zhytomyr Polissya and on carbonate soils of the Western Forest-Steppe, and the analysis of the survival rate of Poplar plantings was conducted on chernozems of the Right-Bank Forest-Steppe. It was established that on sod-podzolic soils, five-year-old plants of Walnut had an average height of 91.8 cm. At the age of 4, some of them bore fruit. The fruit-bearing trees had higher indicators of average height of 13.4% and a diameter of 71.5% compared to the rest. On carbonate soils, the trees showed substantially better growth in height, which is explained by the calciphile nature of the nut. It is determined that an effective way to increase the survival rate of one-year-old seedlings of Poplar varieties Dorskamp, Robusta and I-45/51 is to plant them without trunks. In all the examined varieties, during the first two years, the highest survival rate of seedlings was in the variant without a trunk – from 57.0 to 68.9%, while in seedlings with a trunk – from 50.3% to 68.1%. In 2022, due to irrigation, the survival rate ranged from 74.4% to 88.9%. The average height was mostly also higher in plants that grew from seedlings without a trunk. It was the largest in plants of the Dorskamp clone – 188.6 to 209.3 cm. In uncut plants of this variety, it ranged from 174.0 to 197.2 cm. The practical importance of the study lies in the possibility of developing new forms of Walnut and Poplar and improving technologies for creating forest lands with their involvement, which can be used in Polissya and Forest-Steppe conditions

Sequestration of Organic Carbon in Sod-Podzolic Sandy Loam Soil

Sequestration of Organic Carbon in Sod-Podzolic Sandy Loam Soil

Effect of Fertilizer Systems on Winter Wheat Yield and Grain Quality in Tillage Systems Involving Traditional and Surface Treatment of Sod–Podzolic Sandy Loam Soil

Effect of Fertilizer Systems on Winter Wheat Yield and Grain Quality in Tillage Systems Involving Traditional and Surface Treatment of Sod–Podzolic Sandy Loam Soil

Yields and grain quality of winter rye cultivated on sod-podzolic radioactively contaminated soil depending on the applied means of chemicalization

Relevance. The effect of mineral fertilizers of various degrees of saturation and the biological preparation Albit on the yields and quality of winter rye grain of the Moskovskaya-12 variety has been studied in a stationary field experiment on the radioactively contaminated sod-podzolic sandy loam soil. Methods. The researchers conducted (2019–2021) at the experimental field of the Novozybkov branch of the Bryansk State Agrarian University established that the highest yield of winter rye grain (4.37 t/ha) was formed when using full mineral fertilizer N90P60K150 against the background of treatment of winter rye plants with biopreparation Albit. Results. Under the influence of the applied means of chemicalization, an improvement in the biophysical parameters of winter rye grain has been noted. The content of raw protein in winter rye grain, depending on the fertilizer systems used, has varied from 11.3 to 13.5% with its highest collection (0.599 t/ha) per unit area when using the N90P60K150 fertilizer system in combination with the biopreparation Albit. The use of the complete mineral fertilizer (NPK) with consistently increasing doses of potassium both separately and in combination with the biopreparation Albit has contributed to a decrease in the specific activity of 137Cs in winter rye grain by more than 2.1 times in comparison with the control.

Influence of biological intensification on the balance of sod-podzolic soil nutrient elements in field crop rotations

The studies were carried out in the Kirov region on sod-podzolic sandy loam soil in a long-time stationary experiment established in 1976. The article provides data (2010-2017) on four fallow-grain-grass crop rotations with various types of fallows, annual and perennial legumes (25-50 %), intercrops (12.5-37.5 %). The purpose of the studies is to compare the influence of some biologization techniques in eight-field crop rotations on the change in soil fertility and the balance of nutritional elements of sod-podzolic sandy loam soil. It is found that the application of low doses of mineral fertilizers (N30P30K30) and various types of green manure crops per rotation has significantly increased the content of mobile phosphorus in the arable soil layer (by 39-46 mg/kg). According to grouping the provision of soils with phosphorus, the content of this element passed into the «high provision» group. The content of exchangeable potassium in the soil remained in the «increased» provision group. In the control crop rotation with clean fallow at a minimum supply of nutrients with mineral fertilizers and root-stubble residues, the balance of nitrogen, phosphorus and potassium was created negative at the intensity of less than 100 %. The replacement of clean fallow for cropped and green manure fallows, as well as the introduction of intermediate cruciferous crops into the crop rotation structure contributed to the positive balance of nitrogen (250.2-484.3 kg/ha) with the intensity of 124-150 %. The biologization factors used in crop rotations favored the creation of a positive phosphorus balance (12.5-148.1 kg/ha) with the optimal intensity of 117-163 % and a positive potassium balance (128.9-395.8 kg/ha) with the intensity above the optimal value of 116-148 %. The most advantageous in terms of productivity and ensuring a positive balance of nutritional elements is crop rotation with two green manure fallows and sowing of stubble and hay cruciferous crops in three fields.

The influence of sowing dates on the formation of the soybean seed yield in the conditions of the Central region of the Non-Chernozem zone

Relevance и methods. In the field experiment in the conditions of sod-podzolic sandy loam soil of the Central region of the Non-Chernozem zone, the influence of four sowing periods (30.04; 05.05; 10.05; 15.05) on the formation of the yield of early-maturing soybean seeds of the variety Svetlayawas studied.Results. When sowing at a later date, the emergence of seedlings was accelerated and a faster development of plants was observed during the growing season. Thus, when sowing on May 15, the duration of the sowing — germination period was reduced by 6 days compared to sowing on April 30, and the duration of the growing season from germination to maturation was reduced by 4 days. When sown on April 30, soybeans reached harvest ripeness steadily in the third decade of August, when sown on May 15, the ripening of soybeans goes to September, which can lead to unstable ripening of seeds, since the temperature regime in September does not meet the requirements of soybeans. The conducted studies have shown that high yields of soybean seeds at the level of 2.73 t/ha can be obtained on the sod-podzolic sandy loam soil of the Central region of the Non-Chernozem zone in favorable weather conditions. The most favorable conditions for the formation of a seed harvest in this region are created when sowing on May 5. When sowing on April 30, decreasesuch indicators as field germination — by 12.7%, plant survival — by 2.2%, the height of the first inflorescence — by 2.6 cm and the biological yield of seeds — by 20.1% . At later sowing dates, there is also a decrease in seed yield by 19.5–40.8% due to a decrease in field germination (by 2.9–4.9%) and the weight of seeds from the plant (by 21.6–32.4%).