Dynamics of the species composition of alfalfa-grass agrophytocenosis depending on technological methods of growing

Abstract

Goal.To highlight the features of the formation of the species composition of the alfalfa-grass mixture, depending on the liming of the soil and the application of phosphorus-potassium fertilizers. Methods. System analysis, field, laboratory, comparative calculation. Results. In the first year of using the herbage during chemical soil reclamation, the alfalfa-grass grass mixture contained 50.4-52.0% of the legume component, without liming - 40.8-42.1%. In the third year of use on the produced plots, alfalfa also dominated the botanical composition of the herbage and occupied 50-53.1%. In areas without chemical soil reclamation, the share of sowing alfalfa has sharply decreased - to 10.5-13.4%. Among the sown cereals in the herbage, tall fescue prevailed. The share of this species grew, reaching a maximum of 41.9-42.4% in the third year of use. The species composition of the herbage significantly changed depending on the mowing. Thus, grasses dominated in the first mowing on non-deoxidized areas, the share of which was 53.9-54.5%, including tall fescue 31.4- 32.2%, timothy grass 15.4-16.8%. The share of alfalfa in the first cut was 25.1-27.3%. Soil liming increased the share of the legume component in the first cut to 46.1-47.4%. The share of grass was also high and amounted to 42.1-42.2%. In the second cut, the proportion of alfalfa increased to 26.1-30.2% in the variants without soil deoxidation and to 65.3-68.0% in the variants with limestone flour. Conclusions.The introduction of limestone flour was the most effective factor in changing the species composition of the studied agrophytocenosis. In the limed areas, the share of alfalfa was high during all three years of grass stand use and amounted to 50.0-59.2%. Of the studied perennial grasses, tall fescue was noted to have high coenotic activity, the dominance of which increased in the second and, especially, the third cuttings.