Ефективність азотного удобрення на багаторічному злаковому лучному агрофітоценозі в умовах південної частини Лісостепу Західного

Abstract

Goal. To determine the influence of nitrogen fertilizer on the productivity and botanical composition of sown cereal grass on the slope and economic efficiency of mineral nitrogen application on dry meadows of the Southern part of the Western Forest-Steppe. Methods. Field — to account yield of green mass, laboratory — to determine the dry matter content, statistical — to mathematically process the yield data by analysis of variance, comparative — to determine the economic efficiency of the studied methods of growing perennial grasses. Results. The highly productive use of sown cereal grass is impossible without fertilizers. Thus, on average for 5 years of use, the productivity of sown cereals without fertilizer was 3.72 t/ha of dry matter. With the application of nitrogen fertilizer at a dose of N30 under the 1st mow, it increased by 1.05 t/ha compared to the control. The further increase in the rate of nitrogen fertilizer application to N30 under the 1st and N30 under the 2nd mows ensured an increase in productivity to 5.57 t/ha of dry matter. The productivity of cereal grass was high with the introduction of N60 under the 1st and N30 under the 2nd mows. The total dry matter yield in that variant of fertilizer was 6.61 t/ha, the payback of 1 kg of nitrogen fertilizers — 32.1 kg of dry matter. However, with the introduction of N30, the payback of 1 kg of nitrogen fertilizer the yield was higher and amounted to 35 kg of dry matter. In the variant without fertilizer, on average, for 5 years of use, a grass stand with a predominance of perennial grasses was formed, but nitrogen fertilizer increased the share of cereal components by 9.4–17.2%. The application of nitrogen fertilizer proved to be an economically feasible way to increase the productivity of sown grass. Thus, the highest conditional net profit on average for 5 years of grass use was in the variant with the application of N90 with different distribution of nitrogen under the mows during the growing season (N60 — under the 1st, N30 — under the 2nd mows) — 5.38 thousand UAH/ha. Conclusions. On the gray forest soils of the Western Forest-Steppe on sown cereal grassland application of mineral nitrogen in doses from N30 to N90 increased productivity of grassland by 28–78%, and increased the share of perennial grasses in the agro phytocoenosis by 9.4–17.2%. The payback of 1 kg of nitrogen fertilizers was high and made 31–35 kg of dry matter. On average, for 5 years of use of grass the highest conditional net profit was obtained in the variant with the introduction of N90 (N60 — under the 1st and N30 — under the 2nd mows).