Changes in the nitrogen concentration in the organs of winter wheat varieties depending on the agricultural production system

Abstract

Our aim was to characterize the changes in N% by organs of Tr. aestivum L. varieties, grown in transition to organic production (TOP) and conventional production (CP) during the period 2018-2020. The varieties - Dragana, Rada, Pchelina, Kocara and Kalina were grown after predecessors - winter oil rape, spring peas, sunflower and maize for grain. At CP, fertilization was on a PK background of P60 K 60 and after peas 0, 30, 60 and 90 kg N/ha, and after the others - 0, 60, 120 and 180 kg N/ha. In TOP, the leaves N% is influenced to the maximum extent by the type of the predecessor. In CP however, mineral fertilization has a determining role for the dynamics of N% in leaves, stems and grain, while that in the non-grain part of the spike - the conditions of the year. Cultivation after a maize predecessor results in higher N% remaining in the organs of the noneconomic part of the crop. At CP, wheat forms a grain with the highest protein content after winter oil rape. As with TOP, the varieties Pchelina and Rada are distinguished by a higher protein content compared to the others. Nitrogen concentration in the organs of wheat grown under CP is higher than the same under TOP. Significant dynamics by year was found in the N% in the leaves, where the excess was respectively 87.85% (2018), 78.89% (2019) and 18.47 (2020). For grain, these values are respectively - 38.15%, 25.40% and 9.03%.