Сhanges in soil fertility indices under radiant grasses under different fertilizer systems

Goal. Establish the size of the accumulation of root mass, symbiotic nitrogen by alfalfa, soil fertility and balance of essential nutrients in the cultivation of alfalfa-cereal mixtures under the action of lime and fertilizers. Methods. Field, laboratory, mathematical and statistical. Results. The results of research on the accumulation of perennial grasses and symbiotic nitrogen, cellulase activity, erosion resistance and changes in soil fertility, as well as the balance of essential nutrients in the cultivation of alfalfa, alfalfa and cereal agrophytocenoses under the influence of lime and 2019–2021 in the Forest-Steppe zone of Ukraine on dark gray podzolic coarse-grained coarse-grained soil. Conclusions. Under the action of symbiotic nitrogen of alfalfa sowing in single-species sowing and alfalfa-cereal mixtures and mineral nitrogen at a dose of N90 on cereal grass increases the accumulation of dry roots by 0.99–1.90 t/ha, productive effect of roots – by 0.19–0,64, cellulase activity of soil – by 3-4% and anti-erosion resistance of meadow agrophytocenoses by duration of erosion of soil monolith – by 1:04–1:42 min: sec, as well as accumulation of alkaline hydrolyzed nitrogen in soil. 56–307 kg / ha of nitrogen, 12–45 kg of phosphorus and 87–263 kg/ha of potassium are harvested with different types of meadow grasses. Nitrogen balance on alfalfa and alfalfa-grass stands without nitrogen backgrounds – positive within 15–28 kg/ha, on grass grass with N90 application - close to neutral, and on grass without nitrogen – negative (–18 – –28 kg/ha). The balance of phosphorus for the application of P45K90 on cereals is positive (24–32 kg/ha), and on alfalfa and alfalfa – close to neutral, without fertilizers – negative (–12 – –40 kg/ha). Potassium balance – negative with a deficit of –56 – –241 kg/ha, except for cereal grass for the application of P45K90 where it is close to neutral.