No 7 (2023)

In the Central region of the Non-Chernozem zone of Russia on sod-podzolic light loamy soil in a long stationary experiment in flax crop rotations, the process of replenishing humus due to crop-root residues was studied. Alternation of crops in the crop rotation in 2004–2011: pure steam – winter rye with sowing of perennial grasses (red clover and timofeevka) – perennial grasses of the 1^st year of use – perennial grasses of the 2^nd year of use – flax – potato – barley – oats. In 2012–2018, potatoes were excluded from the crop rotation. The contribution of cultivated crops to the accumulation of soil organic matter varied. The largest amount of crop-root residues (6.8 t/ha) remained in the soil after harvesting perennial grasses, which provided a positive humus balance of +1.35 t/ha. In the crop rotation with potatoes without the use of fertilizers, the humus deficit was –0.20 t/ha, with the exclusion of potatoes from the crop rotation, the deficit decreased to –0.05 t/ha per year. The use of fertilizers increased the productivity of crop rotations by an average of 75%, the amount of crop-root residues increased by 10.6 t/ha or 58%, which allowed to obtain a positive balance of humus in the soil. The use of fertilizers at a dose of (NPK)200 (manure 5 t/ha + (NPK)135 and manure 5.7 t/ha + (NPK)120) in an 8-pole crop rotation with pure steam and potatoes when saturated by 25% with perennial grasses provided a humus balance of +0.17 t/ha per year, in 7-full crop rotation with pure steam and without potatoes at saturation by 28.5% with perennial grasses – +0.43 t/ha per year.

The results of a 5-year study of changes in the botanical composition of seeded and natural herbage, soil properties depending on the applied agricultural techniques, which included direct sowing of grasses into the turf of the developed peat bog and the use of mineral fertilizers, are presented. The introduction of mineral fertilizers contributed to the enrichment of the soil with available nutrients, which made it possible to increase the productivity of herbs in combination with sowing by 2.0–4.7 times, to improve their quality by optimizing the botanical composition of the herbage. It was found that the use of mineral fertilizers in doses of N60P60K90 and N60P90K120 in variants with natural and cultural phytocenoses provided an increase in the proportion of valuable legumes and cereals, reducing the proportion of various grasses from 53 to 25–34%.

One of the reasons for the decrease in the yield of crops is the retardant effect of fungicides. In addition, many fungicides have a toxigenic effect on the mycelium of the fungus. The combination of a fungicide and a plant growth stimulant in a complex preparation can help to reduce the level of the negative effect of the pesticide. It is proposed to introduce individual growth regulators and their combination into the composition of the seed protectant in doses of 50, 100, 200 g/l. The length and the weight of the root and shoot of seedlings under the influence of the seed protectant were less than in the control, and the weight of the endosperm of grain was greater. Under the influence of the seed protectant and gibberellic acid, the length of the shoots corresponded to the control, but their weight was decreased. Indolylbutyric acid, added to the seed protectant, contributed to the effective consumption of spare substances of the endosperm of grain and root growth. Under the influence of the protectant and diphenylurea, the length and the weight of the shoot increased significantly in a balanced manner. The composition of the protectant and the named growth regulators in minimal doses affected the growth of the roots and shoots in the best way of all variants. Preference should be given to low doses of phytohormones and their combination.

The transition from conventional soil treatment technology to zero treatment technology contributes to an increase in carbon sequestration (Sorg) in the form of carbon dioxide (CO₂) from the atmosphere into the soil and, as a result, a reduction in the adverse effects of the greenhouse effect on the ecological state of the environment. The effectiveness of the application of zero tillage is to a greater or lesser extent due to specific agro-climatic conditions, crop rotation systems, fertilizers and plant protection, soil quality and stability. The influence of zero tillage on the dynamics of sorghum reserves and greenhouse gas emissions (CO₂, N₂O, CH₄) in the agro-climatic conditions of crop production (LLC “Orlovka AIC”, Samara region) was investigated. The study was conducted on agrochernozem heavy loam in September–November 2021 in conditions of an abnormally arid growing season and high summer temperatures. On plots with zero tillage, plant residues were received: 268–1720 kg С/ha, 3–66 kg N, 0.2–7.7 kg P and 12–44 kg K/ha. Based on the results obtained, recommendations are proposed for further improving the efficiency of zero tillage technology due, firstly, to reducing its adverse effect on the density of soil composition, and, secondly, taking into account the influence of underlying parent rocks and relief on water erosion of soil and redistribution of granulometric fractions of soil in the agricultural landscape, which will allow using this technology according to principles of adaptive landscape farming.

The design of the device for a hinged rod sprayer of plants for edge processing of the field by the main method of spraying of litter and pests is proposed. The average number of droplets deposited on the surface per 1 cm² at a distance of up to 15 m meets the agrotechnical requirements for the use of herbicides, as well as insecticides and fungicides. According to the height of the cards at a distance of 10 m from the nozzle, the number of drops per 1 cm² decreased, and especially with an increase in the height of their location from 69.7 to 17.5 and 31.7 pcs/cm². At a distance of 15 m from the nozzle, the droplets were small and practically did not settle on the cards. When the vehicle is moving 7.2 km/h (2.0 m/s), the total mass flow of the working fluid of 2 slot sprayers LU-04.AD-04 (color code – red) and 2 slot sprayers LU-02.AD-02, (color code – yellow) at a pressure of 4 The bar was 45.5 g/m linear. It took 45.5 liters of working fluid to work 1 km of the forest belt. For example, a capacity of 600 liters is sufficient for edge processing along the perimeter of a field with a length of 13.2 km. The developed technical means will ensure the effective treatment of protective forest plantations from weeds and pests.

The results of radiation monitoring of sod-podzolic soils of reference agricultural plots of the Ivanovo region, conducted in 2014 and 2021, are presented. Background values of the specific activities of the studied radionuclides in the soils of reference sites have been established. According to the pollution density of the arable horizon of soils ¹³⁷Cs and ⁹⁰Sr, the level of the ecological situation was determined, which made it possible to attribute the soils of all reference areas of the region to uncontaminated territories suitable without restrictions for agricultural use. The power of the exposure dose of gamma radiation of soils and the contribution of ⁴⁰K and ¹³⁷Cs to the formation of the gamma background of soils were determined. Correlation analysis determined the influence of individual physical and chemical properties of soils on the behavior and distribution of radionuclides in the soil and the relationship between the content of the radionuclides themselves. Based on the values of the specific activity of ¹³⁷Cs and ⁹⁰Sr in plant products grown in 2014 and 2021, rows of cultivated plants with a decreasing ability to accumulate these radionuclides from the soil were constructed. All grown plant products of all types of crops fully met the veterinary standards required to limit the content of ¹³⁷Cs and ⁹⁰Sr in plant feeds (green mass, straw and feed grain). The coefficients of accumulation and transition of ¹³⁷Cs and ⁹⁰Sr from soil to plants are calculated. The coefficients of linear correlation between the values of the specific activity of ¹³⁷Cs and ⁹⁰Sr in soils and plants revealed the strength and nature of these dependencies.

The application of agrogeochemical technologies aimed at restoring agrogeochemical cycles in agricultural ecosystems, primarily in the microbial link regulating CO₂ flows, is considered. Examples of recultivation of disturbed and polluted soils, waterlogged and/or over-dried soils are given and their impact on the amount of CO₂ flux is estimated. A complex of agrogeochemical technologies aimed at assessing and stabilizing the microbial link of the biogeochemical cycle in agroecosystems is presented. Examples of the use of these technologies for the regulation of CO₂ emissions in agroecosystems are given. Using one of these technologies, an almost 5-fold decrease in the rate of CO₂ flows during the reclamation of disturbed pasture ecosystems of the tundra is shown. It is necessary to further develop and use agrogeochemical technologies aimed at restoring biogeochemical cycles in agroecosystems, primarily in the microbial link regulating CO₂ flows.