The efficiency of the use of mineral fertilizers on dry meadows of Prykarpattia

Abstract

Goal. To determine the patterns of formation of productivity of sown cereal grass and feed quality indicators depending on the doses and ratios of mineral fertilizers on sod-podzolic soils of Prykarpattia. Methods. General scientific — hypotheses, inductions and deductions, analogies, generalizations; and special — field, laboratory, mathematical and statistical, computational and comparative. Results. Of the mineral elements, nitrogen had the greatest effect on grass productivity and chemical composition. With the introduction of the total dose of N75 with uniform distribution of nitrogen under each of the 3 slopes on different backgrounds of phosphorus-potassium fertilizers, the productivity of cereal grass increased by 2.82–3.06 t/ha of dry weight, with the introduction of N150 — by 3.33–4.93 t/ha, or respectively 1.8–2.1 and 2.5–2.9 times. With the introduction of N75, the content of crude protein in the dry mass increased by 2.9–3.2%, with the introduction of N150 — by 4.2–5.4%, or 1.2 and 1.4 times, respectively. The application of nitrogen fertilizers also increased the content of protein, calcium, magnesium, feed units, metabolic energy, dry matter digestibility, the supply of feed unit with digestible protein, and decreased the content of nitrogen-free extractives and potassium. Conclusions. The dependence of the productivity of cereal agrocenosis on sod-podzolic soils of the Carpathian region on doses and ratios of N, P, K of mineral fertilizers is described by a polynomial of the 2nd degree. The most influential mineral element in terms of increasing productivity and improving feed quality is nitrogen. It provides the highest payback of 1 kg of fertilizer by increasing the yield of dry mass, which for the application of N75 is 38–41 kg of dry weight, which is 4–5 kg more than at the application of N150. Nitrogen fertilizers improve the uniform distribution of the crop on the slopes and increase the content of crude protein. Yield increase from the application of P60, K90, P30K45 or P60K90 on different nitrogen backgrounds is 0.28–1.34 t/ha with a payback of 1 kg of active substance 5–14 kg of dry weight.