Carbonate Chernozem Research Articles

Влияние биологических и гуминовых препаратов на динамику подвижных форм азота в черноземе обыкновенном при возделывании нута

The results of a field experiment to study the influence of biological preparations on the dynamics of mobile forms of nitrogen in 2021-2023 are presented. The tests were carried out in the conditions of the Rostov region, on ordinary carbonate chernozems. The experimental design included bacterial (“Planriz”, “Geostim”) and humic (“BIO-Don 10”, potassium humate) preparations, as well as different nutrition levels (without fertilizers and azofoska 250 kg/ha). Mineral nitrogen is characterized by high mobility; data on hydrothermal conditions and the dynamics of ammonium and nitrate nitrogen by year and nutrition level are presented. It has been established that the use of humic preparations stimulates plant nutrition, which is expressed in negative dynamics compared to the control; this effect is enhanced by the combined use of bacterial and humic preparations. As a result, an increase in yield up to 28.0 % compared to the control and up to 24.9 % compared to the background.

Soil Microbiota and Particulars of Formation thereof under Traditional and Organic Farming on Chernozem Soils of Northern Kazakhstan

The subject matter of the study is soil microbiota of southern carbonate chernozem and particulars of formation thereof under organic and traditional methods of wheat growing under conditions of Northern Kazakhstan. It has been found that soil microbiota varies with arable farming systems. Application of leguminous and cereal above-ground biomass as organic fertilizers contributed to higher numbers of immobilizers that were twice as high as traditional farming variants. When applied as green manure, sweet clover above-ground biomass increased the number of ammonifying soil organisms (up to 6 million CFU/g a.d.s.), while bromegrass biomass increased the number of immobilizers (83.0 million CFU/g a.d.s.) and fungi (8,0 thousand CFU/g a.d.s.). Cellulose-destroying microorganisms were actively propagating in wheat crops (65.0 CFU/g a.d.s.) where wheatgrass biomass was applied as green manure, while sweet clover biomass, on the contrary, contributed to decrease thereof. Under traditional farming conditions, the introduction of ammonium nitrate into rows when planting crops at a dose of N80 stimulated the development of cellulolytic microorganisms and inhibited the development of ammonifying fungi and bacteria. Ammonifiers and immobilizers were actively propagating with reserve application of ammophos in the fallow at the rate of P40.

Фауна и биотопическое распределение гамазовых клещей (Acari: Mesostigmata), в гнездах береговой ласточки (Riparia riparia (Linnaeus, 1758)) на территории Саратовской области

The basis for the article was entomological collections from the nests of the sand martins (Riparia riparia (Linnaeus, 1758)) collected in the Saratov oblast in 2019–2022. A total of 12 colonies were examined in the Voskresensky, Krasnoarmeysky, Lysogorsky, Rivne, Engelssky and Khvalynsky districts of the Saratov oblast, as well as in the city of Saratov. Gamasid mites were collected using a Tullgren funnel for two to three hours and then identified. In each of the studied colonies, a soil section was laid and its morphological description was carried out. As a result of studies of the fauna of gamasid mites in nests, 21 species from 10 families were identified (Laelapidae, Haemogamasidae, Ascidae, Ologamasidae, Ameroseiidae, Dermanyssidae, Macrochelidae, Melicharidae, Pachylaelapidae, Rhodacaridae). The largest numbers and species diversity are characterized by colonies located in residual carbonate chernozem on limestone (12 species, 6719 specimens), the smallest in a colony located in dark chestnut soil on sand (3 species, 339 specimens). The dominant group consists of 3 species: Androlaelaps casalis (Berlese, 1887) – ectoparasite, obligate nest-dwelling mites, Stratiolaelaps miles (Berlese, 1892) and Hypoaspisella lubrica (Oudemans & Voigts, 1904) – free-living gamasid mites, facultative nest-dwelling mites.

Efficiency of foliar additional fertilizing of corn at different periods of application

The studies were carried out on ordinary carbonate chernozem in the zone of sufficient moistening in the Stavropol region in 2021–2023. The effectiveness of foliar additional fertilizing with fertilizer Batr Zinc (1.0 l/ha) was studied on corn hybrids Mashuk 220 MV and Mashuk 355 MV in the 5 and 8 leaves phases. Additional fertilizing was carried out on a background without any mineral fertilizing, as well as backgrounds of nitrogen (N30) and complete mineral fertilizing (N30P30K30). Data were obtained on the terms influence of foliar additional fertilizing with fertilizer Batr Zinc on the corn plants height, the yield of green mass and grain, and crop structure elements. Foliar additional fertilizing of corn in 5 or 8 leaves phases with fertilizer Batr Zinc at a dose of 1.0 l/ha had a positive effect on plants growth. Without the use of mineral fertilizers in the flowering phase, the plants height of the hybrid Mashuk 220 MV increased on average for 2021–2023 by 14 and 16 cm, hybrid Mashuk 355 MV – by 17 and 23 cm. On average, over 3 years without the use of mineral fertilizers, corn fertilizing in the phases of 5 or 8 leaves with fertilizer Batr Zinc increased the yield of green mass of the hybrid Mashuk 220 MV by 5.2 and 6.0 t/ha (15.1 and 17. 4 %), hybrid Mashuk 355 MV – by 7.7 and 6.8 t/ha (23.2 and 20.5 %). Depending on the fertilizing terms, the grain yield of the hybrid Mashuk 220 MV increased by 0.59 and 0.63 t/ha (9.2 and 9.9 %), of the hybrid Mashuk 355 MV – by 0.83 and 0.74 t/ha (12.9 and 11.5 %). There was no significant difference in the yield of green mass and grain between the fertilizing terms. Against the background of mineral fertilizers, foliar additional fertilizing with the agrochemical Batr Zinc was ineffective.

The effect of different doses of ammonium nitrate on the yield and protein content in spring triticale grain

The article presents the results of studying the effect of various doses of ammonium nitrate on the yield and protein content in spring triticale grain. Numerous studies around the world have established that nitrogen is a key factor influencing the productivity of grain crops. The paper presents the results of a 5-year study (2018-2022) of cultivating spring triticale using fallow and stubble predecessors. Nitrogen fertilizer was applied when sowing in rows at a dose of 20 to 80 kg/ha in the active substance. The experiments were carried out in the Akmola region (LLP "SPCGF named after A. Barayev") on southern carbonate chernozem. Over the five years of research, only 2018 was characterized by optimal hydrothermal conditions during the triticale growing season, the remaining four years (2019-2022) were dry. The reserves of productive moisture in the meter layer of soil before sowing triticale in fallow were 119-138 mm, in stubble - 119-125 mm. The content of N-NO3 in the soil layer 0-40 cm before sowing triticale varied according to the years of research, so for fallow it varied from 11 to 28 mg/kg, and for stubble from 10 to 17 mg/kg of soil. The amount of P2O5 before sowing (in the soil layer of 0-20 cm), regardless of the predecessor, varied within 24-37 mg/kg of soil. It was not possible to establish a reliable effect of different doses of ammonium nitrate on grain yield and protein content in triticale grain using the two studied precursors. A strong correlation between the dose of nitrogen fertilizer and the yield of triticale based on the steam predecessor was established only in 2020 (r = 0.85) and in 2021 (r = 0.83). For stubble, a strong positive correlation between nitrogen doses and yield was noted in 2019 (r = 0.78), 2021 (r = 0.79) and 2022 (r = 0.87). A correlation between the protein content in triticale grain and nitrogen doses was established based on the fallow in 2 of 4 years (r = 0.86...0.96). For the stubble, a strong positive relationship was noted in all years of research (r = 0.83...0.99).

Влияние жидких минеральных удобрений на фосфатный режим чернозема обыкновенного при возделывании нута по технологии No-Till

The article presents the results of a production field experiment on ordinary carbonate chernozem for 2022–2023. The influence of liquid mineral fertilizers (LCF 11:37:0 and UAN-32) on the content of available phosphorus in the soil when cultivating chickpeas using No-till technology was studied. It has been established that the application of LCF and UAN increases the content of phosphorus available to plants in the soil during the entire growing season of chickpeas, which confirms the prolonged nature of their action. The effect of liquid mineral fertilizers on the phosphate regime of the soil depends on their type, dose and phase of development of chickpea plants. The greatest changes in the content of available phosphorus in ordinary chernozem were established when using liquid and LCF and LCF with UAN at a dose of 100 l/ha. Keywords: LCF, UAN, CHERNOZEM, MOBILE PHOSPHORUS, CHICKPEAS, NO-TILL TECHNOLOGY

Use of hybridization to develop new sorghum varieties and hybrids

Hybridization is the main method for developing new breeding material, obtaining genetic variability, and combining desired traits. The purpose of the current work is to characterize new promising varieties and hybrids of sweet and grass sorghum developed by the “ARC “Donskoy” because of hybridization on a sterile and fertile basis. The study was conducted on the breeding field of the FSBSI “ARC “Donskoy”, Zernograd, Rostov region in 2021–2023. The zone is characterized by ordinary carbonate chernozem (3.2 % of humus, 10–40 mg/kg of phosphorus, 70–110 mg/kg of nitrogen, 300–500 mg per kg of soil of potassium). Meteorological conditions during the years of study (2021–2023) were contrasting: in 2022, HTC = 0.52 indicated average aridity and insufficient moisture with 0.81–0.82 in 2021 and 2023. The objects of the study were the varieties and hybrids of Sudan grass and sugar sorghum developed by the FSBSI “ARC “Donskoy”. As a result of hybridization on a sterile basis, there was developed a number of sorghumSudan hybrids (‘Jetta x Kudesnitsa’, ‘APV-1115 x Topolina’, ‘APV-1115 x FP’, ‘Dobrynya’, ‘Gordey’) and sweet sorghum hybrids (‘APV-115 x Yuzhnoye’, ‘Jetta x Severanay Vishnya’, ‘Duet’), allowing to obtain green mass yields of 51–63 and 47–49 t/ha, which was higher than the standard by 5–17 t/ha (10.8–37.0 %) and 5–7 t/ha (11.9–16.7 %) respectively. Using intervarietal hybridization, almost all varieties developed by the FSBSI “ARC “Donskoy” have been created. Among them there are the Sudan grass varieties ‘Alisa’, ‘Gratsiya’, ‘Anastasiya’, ‘Kudesnitsa’, ‘FP’ and the sweet sorghum varieties ‘Yuzhnoe’, ‘Feniks’, ‘Orfey’, ‘SK-20/334’, ‘Severanay Vishnya’ with a green mass yield of 40–48 and 34–38 t/ha, which is higher than that of standard varieties by 3–11 t/ha (8.1–29.7 %) and 7–11 t/ha (25.9–40.7 %), respectively. Thus, hybridization is the main method for developing new breeding material and combining the desired traits in new samples.

Influence of weather conditions and elements of harvest structure on yield of spring triticale cultivated in organic agriculture on southern chernozem of northern Kazakhstan

The article presents the results of research on the influence of weather conditions and organic fertilizers on the elements of the crop structure and the productivity of spring triticale. The studies were carried out in the LLP " SPCGF named after A. Barayev" on southern carbonate chernozems in 2018-2021. Triticale was cultivated according to the falow. Dry above-ground mass of sweet clover, sainfoin, alfalfa, brome and wheatgrass was introduced into the fallow field as organic fertilizers. An annual decrease in the grain yield of spring triticale was noted over the years of research from 1.95 t/ha in 2018 to 1.01 t/ha in 2021. The weight of 1000 grains did not change significantly over the years of the study and ranged from 37.0-45.7 g. The number of triticale grains per unit area gradually decreased over the years of the study from a maximum in 2018 of 6951 pieces/m2 to a minimum in 2021 of 2739 pcs/m2. Variants of application of aboveground biomass of various perennial grasses as organic fertilizers had an equivalent effect on the yield of triticale and crop structure elements in comparison with the control (aboveground biomass of sweet clover). A positive correlation was obtained between the yield of triticale and HTC (according to Selyaninov) for the months of June and August, where the dependence on the variants of the experiment changed from medium to high (with June r=0.62 ... 0.94, with August r=0.64 ... 0.80). A moderate correlation was obtained between the grain yield and the HTC (according to Selyaninov) for the period June-August (r=0.59…0.78). The influence of the mass of 1000 grains on the yield was ambiguous, in some cases the relationship was weak (r=-0.21 ... -0.27) in others - medium (r=0.33 ... 0.36). A positive correlation was established between the grain yield and the number of grains per 1 m2 (r=0.61…0.94).

Dynamics of mineral nitrogen in the soil during chickpea cultivation under the influence of bacterial and humic preparations

The article presents the results of a field experiment to study the effect of biological preparations on the dynamics of mobile forms of nitrogen in 2021-2023. The tests were carried out in the conditions of the Rostov region, on ordinary carbonate chernozems. The experimental design included bacterial (Planriz, Geostim) and humic (BIO-Don 10, potassium humate) preparations, as well as different nutrition levels (without fertilizers and azofoska 250 kg/ha). Mineral nitrogen is characterized by high mobility; data on hydrothermal conditions and the dynamics of ammonium and nitrate nitrogen by year and nutrition level are presented. It has been established that the use of humic preparations stimulates plant nutrition, which is expressed in negative dynamics compared to the control; this effect is enhanced by the combined use of bacterial and humic preparations. As a result, the yield increased to 28.0% compared to the control and up to 24.9% compared to the background.

The Influence of Landscape Farming Systems on the Fertility of Eroded Residual Carbonate Chernozem

The purpose of the work is to study the influence of adaptive landscape farming systems on the fertility indicators of eroded residual carbonate chernozem. The study of carbonate soils is of particular scientific and practical interest, since they are susceptible to easy destruction, accelerated degradation and increased difficulty in restoring fertility; they suffer more from water erosion and deflation. With the integrated use of all elements of adaptive landscape farming systems, primarily including anti-erosion organization of the territory that forms the soil-protective configuration of fields, a system of protective forest plantings, adaptive placement of agricultural crops, a fertilizer system aimed at a deficit-free balance of humus and nutrients, even in extremely difficult soil conditions. -relief conditions of the Krasnogvardeisky test site managed to stop soil erosion losses, which contributed to an increase in their fertility.

THE INFLUENCE OF WINTER GREEN MANURES ON THE FERTILITY OF THE SOIL UNDER THE VINEYARD

The paper presents data on the effect of phytoremediation: the use of a mixture of winter vetch and wheat as green manure [GM] and their combination with the microbial preparation Azotobacterin [AB] (GM +AB) in vineyard rows on soil fertility on piedmont carbonate chernozems. A variant with overgrowing of row spacing with segetal vegetation served as a control. The studies were conducted in 2018–2019 in the foothill zone of the Crimea in a vineyard founded in 2002, on grapes of cultivar ‘Bastardo Magarachsky’. Also, GM cultures were sown in November and plowed in May next year. It was found that 0.19–0.21 kg m–2 of organic matter dry mass got into the soil during the plowing with GM, 1.6 times more than in the control. Thus, GM leads to the accumulation of moisture in the layer 60–100 cm, 13.4% higher than the control, and an increase in pHH2O and active carbonates content within the permissible values for grapes. There was an accumulation of organic carbon by 0.31–0.45%, mobile forms of nutrients in the soil: NO3 - by 18%, P2O5 - by 3.2 times, K2O - by 39% in the 0–60 cm layer under the influence of GM.

Maize response to phosphorus and sulfur application on calcareous chernozem in Serbia

Field studies were conducted on carbonate chernozem in Vojvodina Province of Serbia during two seasons of maize growing to adjust nutrient management practices when fertilizers are broadcasted and incorporated into the soil before sowing. The experimental scheme included six fertilization treatments: T1 (zero fertilizer control), T2 (N156P64K64, farmer fertilizer practice), T3 (N100P60K60), T4 (N100P60K60S36), T5 (N100P80K60), and T6 (N100P80K60S48). Nitrogen application practice was found to be excessive, while phosphorus application practice was found to be insufficient. Phosphorus application rate of 80 kg P2O5 ha-1 was found to be rational when the soil test for phosphorus was very low or low. Sulfur (S) application improved grain yield in higher yield conditions, whereas soil containing 3.9–4.0% of organic matter (OM) could meet crop S requirements in lower yield conditions of 5 t ha-1 and below. It is assumed that S application to maize in the southern Pannonian Plain in Serbia may be limited to 36 kg S ha-1.

Application of the GC-MS method in combination with preliminary solid phase extraction on a magnetic molecular imprinted polymer for the determination of bisphenol A in soils of various types

A method of gas chromatography-mass spectrometry (GC-MS) in combination with pre-concentration on a sorbent with BPA molecular imprints (dosage of sorbent — 50 mg, sorption time — 10 min, pH — 3, desorption with methanol) is used to determine bisphenol A (BPA). The sorbent extracts about 96% of BPA from aqueous solutions with a single sorption and is characterized by a high imprinting factor reaching 7.1. The samples of soils of urbanized territories, as well as typical chernozems and residual carbonate chernozems outside the large cities of the Voronezh region were studied. The limit of BPA detection was 0.07 μg/kg (in terms of dry soil), the range of the linearity of the calibration graph was 0.3 – 35 μg/kg. Determination of bisphenol is hindered by soil contamination with petroleum products, which can be eliminated by washing with heptane. It has been revealed that pH of soils has a significant effect on the BPA migration of along the soil profile. The concentration curves of the BPA distribution over the soil profile up to a depth of 1 m were plotted. The maximum BPA concentrations in the soils of urbanized territories depend on the contamination of the territory with polymer waste. The maximum BPA concentrations (29.84 μg/kg) were determined at a depth of 20 cm in samples taken near the landfill of municipal solid waste. At other points within the city limits, the maximum concentrations range within 5.38 – 8.77 μg/kg. Outside the city of Voronezh, the mobility of BPA increases in more alkaline typical and residual-calcareous chernozems and significant concentrations of the pollutant were found at a depth of 50 – 80 cm. The developed scheme can be applied to targeted screening and monitoring of the BPA content. The method can be used for BPA determination in soil horizons for various soil types, meteorological conditions (precipitation, annual temperature regime), and contamination of the territory (the presence of unauthorized landfills, MSW landfills, sewage treatment facilities near the sampling point).

Adaptability of winter triticale varieties on different backgrounds of mineral nutrient in the Middle Don conditions

The research was carried out in order to study the adaptive features of winter triticale varieties depending on the level of mineral nutrition in the soil and climatic conditions of the north-western zone of the Rostov region. The work was carried out on medium-sized southern carbonate chernozem in 2012-2019. The material for the study was 10 varieties of winter triticale of their own selection. The scheme of the experiment included 12 backgrounds of mineral nutrition. The crops were placed on a black steam, the seeding rate was 4 million germinating seeds per 1 he for each agrophone. The agro-climatic conditions during the years of the experiment were contrasting. On average, over the years of research, the most favorable regime for realizing the potential productivity of winter triticale was formed when it was sown at high agrophones (144 ...208 kg of a.s./1 he). At the same time, the average port yield reached the level of 8.11...8.35 t/he of grain. The productive capabilities of all varieties (except Caprice) were high, they amounted to 98...111%. Under contrasting conditions of mineral nutrition, Ataman Platov and Donslav varieties had an optimal ratio between the needs of the genotype and the level of the agrophone. At the same time, they formed the maximum yield in the experiment (8.67 and 8.37 t/he, respectively). The Aztec variety had a wider range of adaptive capabilities than other varieties, so it has a high resistance to a limited amount of fertilizers. The Hector variety was characterized by minimal resistance to nutrient deficiency. According to the optimal combination of parameters of ecological plasticity and stability, the varieties Kapral, Skolot and Donslav were distinguished. In production conditions, they are of some value, since they are able to produce a stable grain yield with various fluctuations in the level of mineral nutrition.

Сравнительная оценка экотоксичности четырех химических форм серебра по ферментативной активности почвы

The study assessed the ecotoxicity of four chemical compounds of silver (nitrate, oxide, sulfide, nanoparticles) by the enzymatic activity of ordinary carbonate chernozem. The effect of nitrate, oxide, sulfide and silver nanoparticles at concentrations of 0.5, 1, 5, 10, 50 and 100 mg/kg on catalase and dehydrogenase activity was evaluated 30 days after contamination. In most cases, the negative effect of nitrate, oxide, sulfide and silver nanoparticles on the enzymatic activity of ordinary carbonate chernozem was noted. The degree of ecotoxicity of silver is affected by its concentration in the soil. Silver nitrate, which is highly soluble in water and provides greater mobility of silver in the soil, has a somewhat greater ecotoxicity. Practically insoluble forms in water (oxide and sulfide) showed slightly less negative effects. As a result of the study, the ecotoxicity series of four chemical compounds of silver were obtained by enzymatic activity: in % of the control by catalase activity (% of the control): nitrate (90) = nanoparticles (90) > sulfide (91) > oxide (92); by dehydrogenases activity (% of control): nitrate (80) > nanoparticles (81) > sulfide (83) ≥ oxide (83).

Green mass productivity and quality of new sweet sorghum varieties in the ARC “Donskoy”

Introduction. In order to realize productive potential of any crop, a variety is of great importance. There is a number of requirements imposed on modern varieties, including not only productivity and quality, but alsocompliance with environmental and climatic conditions, resistance to unfavorable conditions, adaptability to mechanized harvesting. The purpose of the current work was to identify effective methods for developing sweet sorghum varieties, to estimate the sweet sorghum varieties developed by the Agricultural Research Center “Donskoy”” according to productivity and quality of green mass for silage. Methods. The paper presents the study results on the development and research of new sweet sorghum varieties in the Agricultural Research Center “Donskoy”” (Rostov region) through the years 2019–2021. The soil was an ordinary carbonate chernozem, with 3.6 % of humus in the arable layer. The objects of the study were sweet sorghum varieties. The ways to conduct trials, soil tillage and cultivation, as well as zootechnical analysis of green mass were determined according to generally accepted methods. Results. When developing a new variety, a number of characteristicsneeds to be taken into account according to which breeding is carried out from year to year, namely suitability for mechanized harvesting, stem succulence, tillering, stem diameter, length of a vegetation period, sugar content in stem sap, productivity and its main elements, etc. There are such methods for developing sweet sorghum varieties in the Agricultural Research Center “Donskoy”” as hybridization, incubation and selection of constant forms. As a result of the breeding work, there has been developed a number of varieties. In the State List there are 5 varieties of the Agricultural Research Center “Donskoy””. Green mass productivity of the new varieties Yuzhnoe and Feniks was 36 and 42 t/ha, respectively. The sugar-protein ratio of the variety Feniks was normal (1.1 : 1). Silage is recommended to be combined with protein cultures. The yield of exchangeable energy in green mass for silage (for cattle) obtained from new sweet sorghum varieties was 13.5–14.1 MJ/ha.

Sorghum-Sudanese hybrid Dobrynya as a result of heterosis selection

Sorghum-Sudanese hybrids, due to the heterosis effect, have not only increased productivity, but also uniformity, increased vitality, as well as resistance to various diseases and stress factors in comparison with parental forms. The purpose of the work: to characterize the new hybrid Dobrynya, created as a result of heterosis selection, according to the main morphological, biological, economically valuable indicators. The studies were carried out at the Federal State Budgetary Scientific Institution, Agrarian Research Center “Donskoy” (ARC “Donskoy”). The soil of the experimental plot is ordinary carbonate chernozem. The advantages of the hybrid include high foliage (13 leaves per plant) - 39-41% of the leaf mass of plants, good protrusion of the legs (30-35 cm), succulence, tillering, cold resistance. The duration of the period “sprouts-heading” on average for 2019-2022. was 55 days (mid-season), which is 5 days less than the standard. Sorghum-Sudanese hybrid Dobrynya is characterized by a high yield of green mass - 63 t/ha (in total for 2 cuttings) and dry matter - 13.0 t/ha, which is higher than the standard by 28.6 and 31.3%, respectively. -essentially. And in terms of the content of crude protein and the collection of digestible protein, it significantly exceeds it by 1.1% and 0.24 t/ha. According to the results of the assessment in natural conditions, Dobrynya is distinguished by high or practical resistance to loose smut and bacteriosis. The sorghum-Sudanese hybrid has been included in the State Register of Breeding Achievements since 2023 and is recommended for use for green fodder and silage in the Central Black Earth, North Caucasus and Lower Volga regions of Russia.

Influence of polymer modification of complex fertilizer on the efficiency of phosphorus and potassium use by winter wheat on the southern chernozem

In modern conditions of unprecedented challenges, an alternative to the technological degradation of fertilizer application systems can be the development of original forms of long-acting fertilizers. Despite significant progress in the adaptation of progressive systems of agrochemical impacts, the use of traditional forms of mineral fertilizers does not allow using the full potential of the introduced nutrients, since the processes of incomplete denitrification, immobilization and leaching (leaching) of the main macronutrients (NPK), along with the action of urease, lead to unproductive loss of nutrients in the soil. In addition to economic losses, there are negative environmental consequences – eutrophication of water bodies, emission of greenhouse gases. The studies were carried out in 2022 under production conditions in the Kursk district of the Stavropol Territory on the farm of “StavAgroCom” on southern carbonate chernozem. As a modifier of mineral fertilizers, one of the most common synthetic polymers, polyvinyl alcohol (PVA), was used. The polymer consumption rate was 3, 5 and 7 kg per 1 ton of fertilizer. Yield growth was positively correlated with the dose of polymer in the fertilizer. The analysis of soil properties was carried out by the method of principal components. The resulting clustering in the coordinates of the first two components (in total they explain 65% of the data variation) shows significant differences in soil properties under different experimental options. To assess the efficiency of the use of nutrients depending on the dose of the polymer, a differential indicator was proposed – the additional efficiency of the use of nutrients (E). It was estimated from the increase in yield relative to the zero dose of the polymer per unit reduction in the concentration of this element in the soil according to the proposed formula. It is shown that the polymer use in fertilizer gives a statistically significant increase in the efficiency of phosphorus and potassium use by winter wheat.

Оценка урожайности сортов суданской травы разных групп спелости

Abstract. Each region of cultivation requires a set of varieties that are able to make the most out of natural resources. For North Caucasus of Russia, only 6 varieties are approved for cultivation, which are less than 20 years old. Therefore, the development of new Sudan grass varieties has always been an urgent issue for breeders. The variety is the main factor in improving productivity and grain or green mass production. One and the same variety under different cultivation conditions has different plant height, tilling capacity and leaf formation. The purpose of the current study was to determine productivity and adaptability of Sudan grass varieties of different groups of maturity and to identify highly productive ones for the south of Russia. Methods. The objects of the current study were the varieties of different groups of maturity. The study was carried out on the fields of the FSBSI “Agricultural Research Center “Donskoy” in 2019–2021. The soil was an ordinary carbonate chernozem, with 3.6 % of humus in the arable layer. Soil preparation and cultivation activities were carried out in accordance with the agrotechnical recommendations for sorghum cultivation in the Rostov region. The variety adaptability was estimated by the method of L. A. Zhivotkov. Meteorological conditions during the years of study (2019–2021) were contrasting, which made it possible to estimate adaptability of the varieties. Results. There has been established that green mass productivity has a close positive correlation (r = 0.79) with the amount of precipitation and a mean negative correlation (r = –0.59) with the average air temperature. For 3 years of study the most early maturing varieties were at the similar level of 21–23 t/ha in total for two cuts. The variety Yaktik was identified as the most productive in the early maturing group with 31 t/ha. In the middle-early maturing group the variety Gratsiya produced 43 t/ha. In the middle maturing group, the varieties ST-90, Chernoplenchataya 10 and Alisa were the best ones with 43 t/ha, 42 t/ha 41 t/ha, respectively. The mean adaptability coefficient varied within 0.59-1.47. The varieties Gratsiya, ST-90 and Chernoplenchataya 10 have shown the best adaptability to cultivation conditions, being stable in their productivity through the years of study.

Sudan grass productivity depending on meteorological conditions

Productivity of any crop is the potential of the variety when interacting with environmental factors, and especially meteorological ones. Losses due to unfavorable conditions in some years can be up to 50-65,0 %. The purpose of the work was to identify how the productivity of Sudan grass green mass varied through the years with different meteorological conditions, which factors had the greatest effect on it. The study was carried out in 2012-2021 in the conditions of Rostov region. The soil of the plot was ordinary carbonate chernozem. The object of the study was the Sudan grass of Alisa variety, introduced into the State List of Breeding Achievements in 2019. Differences in sowing dates (I-II decades of May) had no effect on green mass productivity and the time of grain maturing. The Sudan grass green mass productivity varied significantly from 36 t/ha to 43 t/ha through the years of study. The year of 2021 was more favorable both in temperature and moisture supply for the formation of the first cut of green mass, and the year of 2018 was favorable for the formation of the second one. The first cut of the green mass was more important and productive. The second cut productivity in 2018 was 84.5 % of the first cut and 45.8 % of the amount of both cuts. In 2021, 35,0 % of the first cut and 26.5 % of the total productivity. The correlation analysis has confirmed that green mass productivity has a close positive correlation with the amount of precipitation (r = 0.79) and a mean negative one with the average air temperature during the vegetation period (r = -0.59).