Impact of Water-Nitrogen Coupling on the Growth Characteristics of Ornamental Sunflowers

As an important resource regulation method in agricultural production, water-nitrogen coupling has a significant synergistic effect on crop growth. This paper takes ornamental sunflower (Helianthus annuus L.) as the research object. By integrating the topdressing of compound fertilizer and the ratio of base fertilizer, it explores the effects of different water-nitrogen coupling modes on its growth, physiological characteristics, and ornamental quality. The results show that appropriate irrigation combined with nitrogen fertilizer application can significantly increase plant height, flower disc diameter, and flowering uniformity. Appropriate coupling of water and nitrogen significantly increases plant height, capitulum diameter and cut - flower yield. Among them, the W3N3 treatment shows the best comprehensive performance.