Effect of ammonium and potassium nitrate on winter hardiness and yield of winter rye (<i>Secale cereale</i> L.)

Abstract

The results of research for 3 years (2019–2021) on winter rye (Secale cereale L.) crops in the North-West region of the Russian Federation (Leningrad region) are presented. The effect of different doses and timing of ammonium and potassium nitrate application on winter hardiness and productivity of winter rye plants on the example of Volkhova and Eureka varieties was studied. The soil in the experimental fields was sod-podzolic loamy with the depth of the arable horizon of 20–25 cm. Humus content – 2.0–2.3%, pH of the salt extract – 5.2–5.5. Fertilizers were applied in dry form in the autumn one week after the emergence of the seedlings, and in the spring – at the resumption of vegetation. The studied fertilizer doses in terms of active substance for nitrogen were 0 (control), 30, 60 and 90 kg/ha. It is shown that winter hardiness of both varieties practically did not depend on the doses and timing of the application, as well as on the type of fertilizers. The maximum grain yield was shown by the Volkhova variety at a dose of nitrogen of 60 kg/ha, the Eureka variety – 90 kg/ha, with the maximum yield of the Eureka variety for all the years exceeding that of the Volkhova variety by 24.5%. Within the specified doses of nitrogen for both varieties, the best option was a single spring application of a mixture of ammonium and potassium nitrate, the worst - a single spring application of ammonium nitrate alone. On average for both varieties, potassium nitrate application in spring increased the grain yield by 16% compared to the variants where potassium nitrate was not used.