Multi-Year Evaluation of Cover Crop Intercropping in Sunflower (Helianthus annuus): Ecosystem Services, Climate Adaptation, and Yield Stability
Peter Streb* and Adrienn Széles
ABSTRACT
Climate change, soil degradation, and increasing biotic stress factors necessitate the development of new, sustainable cultivation technologies. This research evaluates the integration of cover crop intercropping in sunflower (Helianthus annuus) production based on field trials conducted between 2021 and 2025 across multiple European locations. The results highlight that while intercropped sunflowers can achieve yield surpluses in years with optimal precipitation (e.g., France, 2023), extreme drought and heat during the 2024 and 2025 seasons resulted in intense water competition, causing the main crop's yield to fall behind the traditional technology control. However, the intercropping system provides numerous ecosystem services: it improves soil quality, reduces weed pressure, eliminates pre-emergent herbicide phytotoxicity, and significantly increases pollinator activity. In alignment with recent international findings, the trials confirm that the appropriate species composition (e.g., Phacelia and Trifolium species) is critical for the phenotypic development of the sunflower and the overall success of the cultivation system.
