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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.

No abstract

One of the promising high-tech systems for the use of agricultural chemistry can be the development of original forms of agrochemical preparations (fertilizers and pesticides) of prolonged action. The slow-release polymeric composites formed by our technology have a number of advantages. A single injection of preparations during seeding allows avoiding multiple medical top dressings (for fertilizers) and treatments (for pesticides) during the growing season. The most important principle of the effectiveness of using agricultural chemistry is the linking of the timing of top dressings and treatments to the developmental phenophases of both plants and parasites. Much depends on the characteristics of the development of parasites. For example, larvae of cyst-forming nematodes are vulnerable to drugs during migration in soil. However, the cyst-forming nematode of potato develops in one generation for a season, and the cyst-forming nematode of beet develops in 3–4 generations. In the latter case, additional use of modified forms of nematicides is possible. In favor of drugs with prolonged action (apart from a multiple increase in economic efficiency, especially in the event of a shortage of the drug), we should attribute the technological possibility we have worked out to program the action of drugs. We have adopted the following reference terms for prolongation, 1, 3 and 6 months. Technologically, this is achieved by the polymer concentration in the composite. In this case, our method can be used to take into account weather risks.