Features of nutrient intake and removal by winter wheat variety Skipetr under the influence of nitrogen fertilization

Abstract

The differences in weather conditions and rates of base fertilizer application and top dressing influenced the accumulation of nutrients in plants during the main stages of development. In 2022, nitrogen intake was higher and potassium consumption was lower than in 2023. Lower phosphorus content was found. Regarding the optimal levels determined by V.V. Zerling, basically on both years they were lower in nitrogen at the tillering and earing stages; phosphorus content level was insufficient any time, especially in 2023. In terms of potassium content, there was shortage during the stem elongation in 2022; and in 2023 there was its excess. Under the influence of ammonium nitrate fertilization, nitrogen intake increased on both years at the spring tillering stage. The nutrient content level in the aerial part affected nutrient accumulation in seeds; in 2022, the levels of nitrogen and phosphorus were higher, and potassium level was lower than in 2023. Moreover, on both years, nitrogen fertilization contributed to increased nitrogen content and did not affect the content levels of phosphorus and potassium. Taking into account the resulting yield, the removal of nitrogen from grain varied in 2022 according to fertilization variants in the range of 84.3-107.4 kg ha versus 75.6 kg/ha in the control; and in 2023 - 102.9-171 kg ha versus 105.6 kg ha, and it was the highest one on both years with twofold fertilization with ammonium sulfate at tillering and ammonium nitrate at earing stage. The removal of phosphorus generally exceeded the background and amounted to 14.3-20.3 kg ha in 2022 and 13.8-17.3 kg ha in 2023; and in 2023, potassium removal with the harvest was 29.5-38 kg ha, while in 2022 - 13.3-16 kg ha. The change of phosphorus and potassium removal from seeds in the variants was associated to a greater extent with the yield values. The evaluation of the effect of fertilization in terms of yield and nutrient removal showed they were the greatest with twofold fertilization at tillering with ammonium sulfate (N₃₀ and N₃₅) and at the stages of stem elongation and earing with ammonium nitrate (N₃₅). Taking into account the formation of the highest yields and the content of primary nutrients in plants and seeds, for the Skipetr variety, the following may be considered the optimal levels: nitrogen at spring tillering - 2.8-3.75%, phosphorus - 0.23-0.41%, potassium - 2.76-4.27%; stem elongation and earing: nitrogen - 1.16-3.7%, phosphorus - 0.09-0.49%, and potassium - 2.05-5.42%.