Influence of long-term use of mineral fertilizers on the yield and quality of winter rye grain

The studies were carried out in 2018-2019 in the conditions of the Kirov region on sod-podzolic middle loam soil formed on the eluvia of Perm clays. The range of fertilizer doses in the long-term stationary experiment varied from 30 to 150 kg a.i. (active ingredient). With increase in fertilizer doses, the yield of winter rye of Grafinya variety grew from 3.44 t/ha at the dose of P60K60 to 5.94 t/ha at the dose of N150P150K150. Significant addition of grain yield was obtained in all variants except P60, K60 and K120. Maximum addition of grain yield to the control without fertilizers were obtained in variants with application of 120 and 150 kg a.i. /ha NPK − 3.87-4.11 t/ha (LSD05 = 1.2 t/ha). In 2019 the yield of rye varied from 2.65 t/ha in the control variant to 7.08 t/ha by application of a maximum dose of N150P150K150. In 2018 it varied from 1.01 t/ha to 4.81 t/ha, respectively, which was 1.5-2.6 times less, as during the period of grain formation that year the amount of precipitation was 135% from the norm. The highest payback of 1 kg a.i. of mineral fertilizers was obtained by application of ammonium nitrate N60 −42.5 kg of grain. Test weight of grain was significantly higher under favorable growing conditions of 2019 and varied from 696 to 728 g/l. With the increase in doses of mineral fertilizers, there was a tendency to decrease the test weight of grain. The 1000-grain mass of winter rye did not depend on the use of fertilizers and was in the range of 28-33 grams. The content of raw protein in the grain grew with increasing doses of fertilizers, but mainly the grain of the third class of quality with the protein content of 88.1 to 110 g/kg was obtained. Bakery qualities depended on the conditions of moisture supply during grain maturation: in 2018 grain of the second and third commodity classes was obtained, in 2019 – that of the fourth class. If full fertilizer was applicated in the dose N30Р30К30, prime cost of 1 ton of grain was 3.663 rubles with a total profitability of 91.1 %. Application of ammonium nitrate alone in the dose of N60 provided profitability of 156.2 %.