INFLUENCE OF LONG-TERM APPLICATION OF FERTILIZERS ON BOTANICAL COMPOSITION OF HAYFIELD PHYTOCENOSIS AND THE QUALITY OF THE RECEIVED FODDER

In the Federal Williams Research Center of Forage Production and Agroecology in 1947 the study of the effectiveness of mineral and organic fertilizers was started. For 74 years of using the herbage without re-sowing, the features of succession variability have been revealed. There was a reformation of the seeded legume-grass herbage into two types: low grass-legume-motley grass against the background of the use of one- and two-component mineral fertilizers and manure (regressive succession) and grass-motley grass with the application of complete mineral fertilizer with high doses of nitrogen (progressive succession). On the herbage of the first type, the predominant species is the introduced species — red fescue (43.8–75.4%), on the herbage of the second type — high grasses (meadow foxtail, cocksfoot, awnless brome). The reformation of the herbage did not lead to a decrease in yield. Over the past 28 years (average for 1993–2020), the yield of herbage with regressive succession exceeded the control (3.3 t/ha dry matter) by 1.1–1.9 times, with progressive succession by 1.9–2.6 times. The annual consumption of nitrogen by grasses in the control was 54 kg, P2O5 — 14 kg, K2O — 46 kg. The application of one- and two-component mineral fertilizer and manure increases the consumption of nitrogen by 1.1–2.4 times, phos-phorus — by 1.3–3.1 times, potassium — by 1.3–3.6 times, the application of complete mineral fertilizer, respectively, in 2.3–3.5, 2.9–3.9 and 2.4–3.9 times. The quality of the received feed for the content of crude protein, crude fiber and crude ash on both types of herbage met the requirements of standard for the first and second class. The content of mineral elements also met the zootechnical standards.