Impact of Post-Maize Residual Nitrogen on Functional Properties of Grain in Spring and Winter Wheat

Common wheat (Triticum aestivum ssp. vulgare) is one of the three major cereal crops cultivated worldwide and plays a key role in ensuring food safety. Adequate nitrogen supply is a key factor affecting the yield and functional properties of the grain of common wheat. Improving the efficiency of soil nitrogen use can be achieved through the application of appropriate mineral fertilizers and proper variety selection. The aim of this study was to determine the effect of residual nitrogen (Nres) remaining after maize cultivation on the functional properties of winter and spring wheat grain. The results of the present study clearly indicate that appropriate selection of the maize hybrid (preceding crop) and nitrogen fertilization strategy (residual nitrogen, Nres) can significantly enhance the antioxidant potential of grain in both forms of wheat (winter and spring). At the same time, our results highlight the practical importance of agronomic practices in improving the functional value of grain, both in terms of nutritional quality and health-promoting potential. Total polyphenol content in grain was stable, while antioxidant activity (ABTS+, DPPH) depended on genotype × fertilization interaction, particularly in winter wheat. These changes likely result from differences in polyphenol profile and the proportion of other antioxidants. Appropriate cultivar selection and nitrogen fertilization can enhance the antioxidant potential of wheat. No significant effect of either the preceding crop (maize) or its cultivar, or the form of nitrogen fertilizer, was found on the amino acid and total polyphenol content in winter and spring wheat grain. Population growth and the need to ensure adequate food supply highlight the importance of improving nitrogen management efficiency in agriculture by accounting for the amount and quality of residual soil nitrogen after the preceding crop.