Moisture and nutrient management for sustainable dryland sunflower production

Abstract

Abstract Background and Aims Improving agricultural water and nitrogen resource management is a crucial global challenge for enhancing water and nitrogen use efficiency in croplands. This study aimed to understand the intricate interactions among soil, climate, and crop management to simultaneously enhance water use efficiency (WUE) and nitrogen use efficiency (NUE) in sunflower crops in semiarid environments. Additionally, the impact of nitrogen fertilization on grain oil content determination was assessed. Methods Two experiments were conducted at INTA Anguil Argentina, one on loamy and sandy soil (Exp.1) and another with two planting dates during three years (Exp.2). Each experiment included six fertilization treatments. WUE was calculated as the yield-to-water consumption ratio, while NUE was determined by the yield-to-available nitrogen in soil plus fertilizer ratio. Results Texture and available soil nitrogen explained 83% of sunflower crop yield variability. Findings revealed that as sunflower crop yield increased due to higher nitrogen availability and favorable water conditions, water use efficiency improved, while nitrogen use efficiency remained constant even at high nitrogen rates and yields. Sunflower yields in this semi-arid environment increased by up to 54% in loam and 70% in the sand. Importantly, grain oil content was not significantly affected by increased soil nitrogen availability. Conclusion This study demonstrates the feasibility of maximizing both crop yield and water use efficiency by optimizing nitrogen availability in the soil, without compromising grain oil content. No negative relationships were observed between WUE and NUE, highlighting the potential for sustainable agricultural practices in semiarid environments.