Agroecological substantiation of technologies for growing grain crops in the conditions of the Southern Steppe of Ukraine

Agroecological substantiation of cereal crops cultivation technologies becomes especially relevant in conditions of insufficient moisture, as it requires sustainable and efficient agro-production systems that ensure high yields and preserve natural resources. The aim of the study is to determine the impact of nitrogen fertilisation on the growth and development of winter wheat in an arid climate. To achieve this goal, a field study was conducted at the fields of the Educational and Research Centre of Mykolaiv National Agrarian University to study mineral nutrition and the impact of different nitrogen rates on the structure and quality of winter wheat grain yield. The study found that increasing nitrogen fertiliser rates has a positive impact on crop growth and yield. The application of higher nitrogen rates, in particular N60 and N80 in spring fertilisation, increases plant height by 3.8 and 4.6 cm, respectively, compared to N30. In addition, a double increase in nitrogen fertiliser rates resulted in a 3.5% increase in the number of productive stems and a 13.6% increase in the weight of 1,000 seeds. Mineral fertilisers also had a significant impact on winter wheat yields, with Р30К30+N60 and Р30К30+N80 yielding 51.8 and 49.3 c/ha, respectively. The results of laboratory studies confirmed that nitrogen fertilizers in an increased amount lead to a decrease in the starch content in winter wheat grains, while simultaneously increasing the protein content. Correlation analysis showed a tendency to increase the yield of winter wheat with higher application of nitrogen fertilizers, however, in order to avoid deterioration of the quality of crop products, it is important to follow the recommendations. The practical significance of the obtained results lies in optimizing the cultivation of grain crops, as well as increasing their yield in conditions of limited water resources and the threat of drought