No 7 (2024)

The effective and potential fertility of leached chernozem was evaluated in a field stationary experiment at the Central Experimental Field of the Kurgan Research Institute and the application of 2 crop cultivation technologies. In the first part of the experiment, the corn–wheat–wheat–oat crop rotation was studied during annual plowing, in the second – permanent wheat after a stubble background. The first technology was characterized by higher effective fertility, a large number of plant residues, due to which its advantage was manifested in terms of humus content. The positive effect of fertilizers on the indicators of potential soil fertility was manifested when applying the 2nd and 3rd doses of nitrogen against the background of the use of phosphorus.

In 2021–2023, the effect of non-root fertilizer application on photosynthetic activity and yield of plum varieties in the arid zone of the Northern Caspian Sea was studied. It was found that the leaf surface area on average during the growing season in the variant of the combined use of Aquarin + Ultramag boron + + Ultramag calcium exceeded the control by 50%. An increase in photosynthetic potential was noted when treated with Aquarin and Master fertilizers by 25.0 and 42%, respectively. The maximum increase in yield (12.8 t/ha) was obtained during leaf processing in the variant of the combined use of Aquarin + + Ultramag boron + Ultramag calcium preparations, which exceeded the control by 34.7%. It should be noted that the best responsiveness to non-root top dressing was distinguished by the Gigantic variety, whose yield was 13.2 t/ha, which was 39% more than the control.

The study was carried out to evaluate the effect of a nutrient solution for the rhizogenesis of grape micro–gears in the Murasiga-Skuga medium (MS) with the addition of various concentrations of the drug Tiaton (0.1, 0.15, 0.20 and 0.25 ml/l). In experiments, the effect of different concentrations of the drug Tiaton on the rooting and vegetative growth of grapes of the Khasansky and Moskovsky White hybrids in vitro was studied. When the Tiaton preparation was added to the MS nutrient medium in various concentrations, the rooting capacity of the micro-gears of the Khasansky hybrid grape increased by 40%, the total root length increased by 2.4 times compared with the control. In the Moscow White hybrid, when using the Triaton growth regulator, an increase in the rooting capacity of micro gears up to 25% and the total root length by 1.5 times is shown. The optimal concentrations of the Triaton preparation for addition to the MS nutrient solution for optimal rhizogenesis of micro-gears and the development of vegetative growth of cuttings of the studied grape hybrids have been established. Thus, for Khasansky hybrid grapes, the most optimal medium for improving rooting and root development of micro gears was ½ MS + 0.15 ml/l of Tiaton preparation. In the Moscow White hybrid, a significant increase in the rooting capacity of micro-gears and good development of the root system was obtained when Tiaton was added to the nutrient medium for rhizogenase of micro-gears in concentrations (0.15 and 0.20 ml/l).

The wide range of biological activity of essential oils in relation to pests gives reason to consider them as additional plant protection products and in other measures aimed at reducing the number of harmful arthropods. This paper presents the results of a study of the biological activity of a mixture of thymol and carvacrol, which are part of the essential oils of many plants, including oregano Origanum vulgare L. for the peach aphid Myzus persicae. The use of essential oil and a mixture of its components as fumigants has demonstrated their high aphidocidal potential. When processing the leaves of a forage plant (beans), the ability of a mixture of thymol and carvacrol to reduce the viability of female aphids and the number of offspring was established, and on vegetative plants (pepper) to negatively affect the survival of individuals of the daughter generation in the preimaginal period. The short duration of action allows the use of oils and individual components in conjunction with biological control agents and pollinators, and assumes a slight or complete absence of residues in food products. Preparations based on essential oils of plants can be used immediately before harvesting, due to the minimum waiting period.

The results of field experiments are presented, in which the influence of varietal characteristics of grain crops of different breeding periods on the effectiveness of using mineral fertilizers for them on various soils was studied. Special attention was paid to the specific removal of nutrients, which means the consumption of nitrogen, phosphorus and potassium of 1 ton of grain harvest with an appropriate amount of straw. The results of the experiments showed that the studied varieties responded differently to the application of fertilizers. Almost all modern varieties provided higher yields compared to previously zoned ones. The Mironovskaya 808 winter wheat variety on sod-podzolic soil was almost 2 times inferior to the Moskovskaya 39 variety and 1.7 times inferior to the Lgovskaya 4 variety on leached chernozems when applying the same dose of NPK. Similar data were also obtained for spring barley of the Moskovsky 121 variety and NUR and Elf varieties on sod-podzolic soils, where when N60P60K60 was applied, a yield of 2.7 t/ha was obtained in the first case and 4.9 and 4.7 in the second. Identical results were also observed on leached chernozems and light chestnut soils. In experiments with spring wheat, the result was the same, but the yield of this crop was lower compared to winter wheat and spring barley. The varieties of the studied cereals reacted to a lesser extent to changes in the specific removal of nutrients, and the data obtained did not show a sufficiently clear pattern, which necessitates continued research in this direction.

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.

The dynamics of phytotoxicity indicators (germination and length of radish roots) of ordinary chernozem when contaminated with silver nanoparticles was studied. In laboratory conditions, ordinary chernozem was contaminated with silver nanoparticles (1, 10 and 100 mg/kg) for 3, 10, 30, 90 and 180 days. It was found that the more silver nanoparticles were introduced into the soil, the greater the decrease in germination and length of radish roots. There was no restoration of germination and length of radish roots with an increase in the period from the moment of contamination. In this study, the maximum toxic period from the moment of contamination for each indicator was identified by its sensitivity to silver nanoparticles and informativeness. The maximum toxicity of silver nanoparticles in relation to the root length and germination of radishes was noted on the 10^th and 30^th days, respectively. The results can be used to assess the phytotoxicity of soils contaminated with silver nanoparticles.

The question of the study of soil bodies (pedomatrids) independently of soil systems, although raised earlier, has not yet found a concrete reflection in the soil literature. Two groups of quantitative indicators of pedomatrids (granulometric and gross chemical compositions) have been converted to reflect not only their content but also their distribution in the soil profile. A total of 16 indicators were obtained for each pedomatrix. The soil data sample covered a fairly wide area of the European, West Siberian and Central Asian parts of the former USSR. To assess the macrostructure of the data sample, the pedomatrices were grouped according to these 16 indicators. Only a few groups with more than three objects each and many smaller groups with one object each have been found. On the one hand, this seems to confirm the independence of soil varieties from each other, but, on the other hand, the resulting groups are quite heterogeneous, both geographically and in terms of soil classification (according to the soil classifications of the USSR (1977) and Russia (2004)). This confirms the idea of V. O. Targulyan about the necessity of studying the geography and classification of soil bodies, regardless of soils.