Work

Controlled-release fertilizers increase sunflower yield by regulating soil nitrogen, photosynthesis, and root structure in arid regions

Year: 2026

Type: article

Abstract: Background and aims: In arid irrigated systems, nitrogen supply often mismatches crop demand. This study assessed whether controlled-release fertilizers (CRF) better synchronizes nitrogen supply with sunflower demand than traditional nitrogen fertilizer (TNF), by comparing field treatments, quantified soil-root-plant responses, and identified the CRF rate that maximizes yields and nitrogen use efficiency (NUE). Methods: A three-year field experiment (2019-2021) was conducted in the Hetao Irrigation District, Bayannur, Inner Mongolia, China, using sunflower cultivar SH361. Treatments compared CRF and TNF at 135, 225, and 315 kg N/ha. Measurements included soil nitrate (0-100 cm), root traits (surface area density, dry weight), root sap production and sap nitrate, relative chlorophyll values, net photosynthetic rate, plant nitrogen uptake, and yield. Results: , indicating that additional N input beyond 225 kg/ha conferred no yield benefit. Enhanced yield under CRF was strongly associated with higher soil nitrate availability, greater root activity, and increased photosynthesis. Conclusion: CRF improved nitrogen synchrony, yield, and NUE under arid irrigation. The 225 kg N/ha CRF rate provided the most favorable yield-efficiency balance, offering a practical management strategy for sustainable production in water-limited regions. By quantitatively linking CRF to soil-root-plant nitrogen coordination, this study advances understanding of nitrogen optimization in arid irrigated systems.

Source: Frontiers in Plant Science

DOI: 10.3389/fpls.2025.1747095