Four decades of crop improvement decreased specific leaf nitrogen and reshaped canopy trait profiles in maize

Key Points

• Crop improvement decreased specific leaf nitrogen over 40 years, leading to altered canopy trait profiles.
• Specific leaf nitrogen levels showed a significant reduction from the 1980s to present, with implications for crop management.
• Observational analysis highlights changes in canopy traits alongside reductions in leaf nitrogen allocation in maize varieties.
• These findings support the need for further exploration of nitrogen management strategies in modern crop systems.