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The purpose of this study was to identify changes in soil fertility and yields of main crops in a grain–beat crop rotation system as a result of long-term (ten rotation cycles) application of fertilizers in the Central Black Earth Region. Field works were conducted in Voronezh oblast on a low-humic leached chernozem soil. Changes that have occurred over the period from the first rotation cycle (1936–1945) to the tenth rotation cycle (2018–2022) were analyzed. The experiment involved the following variants: (1) control (no fertilizers), (2) N10P10K10 + manure (2.8 t/ha), (3) N20P20K20 + manure (2.8 t/ha), (4) N30P30K30 + manure (2.8 t/ha), and (5) N10P10K10 + manure (5.6 t/ha). The following changes in soil fertility occurred in the 0–20-cm layer over the period from the first to the tenth rotation cycle due to the effect of fertilizers: (1) in variants with the application of N20P20K20 + manure (2.8 t/ha) and N30P30K30 + manure (2.8 t/ha), hydrolytic soil acidity (Hh) increased by 5.26–83.3%, mobile K2O content by 18.9–74.4%, cation exchange capacity by 27.8–35.7%, and mobile P2O5 content by 7.81–9.00%; (2) in the control variant and variants with the application of N10P10K10 + manure (2.8 t/ha and 5.6 t/ha), humus content decreased by 0.41–0.73%, N-NO3 content by 25.3–47.7% and P2O5 by 13.3–31.6%. Long-term application of fertilizers increased grain yields of barley by 11.3–50.1%, grain yields of oats by 4.0–51.2%, grain yields of winter wheat by 13.4–30.6%, and tuber yields of sugar beet by 15.0–36.7%. In addition, it reduced clover fresh yields by 4.9–27.7% and increased by-product yields in all crops by 6.1–23.0%. Over the period from the first to the tenth rotation cycle, fertilized arable land productivity per 1 ha increased by 3.30–18.3% (less yield increase by 960 grain units/ha due to the introduction of more productive modern varieties). Long-term application of N30P30K30 + manure (2.8 t/ha) ensured the highest level of soil fertility and productivity in the crop rotation system. The fertilization scheme was as follows: N135P135K135 applied to sugar beet fields twice per nine-field crop rotation cycle and manure applied to the fallow field once per crop rotation cycle at a rate of 25 t/ha. [ABSTRACT FROM AUTHOR]

The study of the morphological and cultural properties together with the structure of intraspecific differentiation of Septoria blight populations of grain crops makes it possible to substantiate the qualitative composition of the biomaterial, which provides an objective assessment of the resistance of host plants. The aim of this research is to characterize the structure of fungal populations that cause Septoria blight of grain crops in different agroclimatic zones of the Russian Federation in terms of morphological and cultural properties. Within the period of 2021, a study of the morphological and cultural properties of pathogens of grain Septoria blight has been conducted in five grain-producing federal districts of the Russian Federation (South and North Caucasus, Lower Volga, Central, Northwestern). At least 100 monoconidial isolates obtained from each infectious sample were studied. The sizes of colonies, their structure, coloring, and intensity of sporulation are described. Among Zymoseptoria tritici isolates, rapid-growing highly sporulating yeast-like colonies prevailed. In populations from the Rostov and Voronezh oblast, mixed colonies were noted more often. Using the Kruskal–Wallis test, the influence of the conditions that develop during the period of vegetation of the host plant on the morphological and cultural properties of the pathogen is shown. Colonies of the Parastagonospora genus had well-developed powdery, woolly or velvety mycelium. The size of the colonies reached 80–90 mm in diameter. Both the medium and high sporulating activity of colonies were noted. Rare species are described: P. avenae f. sp. avenaria from spring oat of Tambov oblast and Septoria triticicola Lobik from spring triticale and soft spring wheat of Krasnodar krai. The resulting monoconidial colonies of P. avenae f. sp. avenaria were uniform gray in color, formed many pycnidia, and were high-sporulating. Monoconidial isolates of the S. triticicola fungus in pure culture were of the zonal type: in the center of the colony, they were white, gray, and granular, while they were gray with dense felt-like mycelium along the edges with multiple pycnidia and high sporulation. [ABSTRACT FROM AUTHOR]

This paper examines the aftereffect of fertilizers applied for a long time to sugar beet cultivated in a nine-field grain–black-fallow–row crop rotation system in the forest–steppe unstable moistening zone of the Central Black Earth Region on the fertility of leached chernozem soils under grain crops and their yield and quality. The experiment launched in 1936 includes the following fertilizer systems (per rotation): N90P90K90 + manure (25 t/ha), N180P180K180 + manure (25 t/ha), N270P270K270 + manure (25 t/ha), N300P300K300 + manure (50 t/ha), N380P380K380, and a variant without fertilizers (control). Mineral fertilizers are applied to sugar beet twice per rotation; manure is applied to the black fallow field once per rotation. The most significant changes in agrochemical characteristics of the leached chernozem soil (0–40-cm layer) caused by the effects of mineral fertilizers and manure were noted under winter wheat (the P2O5 content increased by 21.3–77.2%, the total mineral nitrogen content (N-NO3 + N-NH4) by 8.1–133.2%, and pHKCl by 0.07–0.37), while the least significant changes were under oats (the P2O5 content increased by 16.3–44.4%). Soil saturation with fertilizers increases the oat productivity to the greatest extent (by 12.2–65.5% in comparison with the control); the effect on barley and winter wheat in the black fallow link is somewhat less (13.0–59.1% and 7.37–57.6%, respectively); and the effect on winter wheat in the clover link is the least significant (29.9–47.8%). The aftereffect of fertilizers increases the protein content by 0.5–1.0% in oat grains and by 0.6–1.8% in barley grains in comparison with the control. A significant positive correlation between the amount of applied fertilizer elements and the yield capacity of barley, oats, and winter wheat was registered in both crop rotation links (r = 0.67–0.95). The following fertilization systems ensure the highest productivity of the grain–black-fallow–row crop rotation system in combination with a satisfactory quality of wheat, barley, and oat grains: (1) N135P135K135 applied to sugar beet twice per rotation + manure applied to the black fallow field (25 t/ha) and (2) N190P190K190 applied to sugar beet twice per rotation (without manure). The additional yield reaches 14.4–16.8 kg of grain per 1 kg of NPK. [ABSTRACT FROM AUTHOR]

The results of studying the changes in the range of insecticides for grain crop protection are presented for the period of more than 20 years. The aspects of extension are assessed for the range of insecticides used for these purposes, the peculiarities of certain chemical classes are shown along with the terms of pesticide application against various types of pests, and the dynamics of the ecological and toxicological properties of the pesticides are reviewed from 1995 up to the present day. The range of plant protection products is analyzed for the period of 1995-2017. It is shown that these changes are a continuous process that is expressed both as an increase in the total number of pesticides and as a qualitative improvement by introducing the new ones or combining the active substances of different content and formulations as well as by improving technologies and methods of pesticide application. [ABSTRACT FROM AUTHOR]