Agroforestry systems can protect yerba mate crops from extreme environmental conditions without altering their secondary metabolites and productivity

Agroforestry systems (AFS) offer sustainable alternatives to monoculture for crops such as yerba mate (Ilex paraguariensis). This study assessed the impact of AFS and monoculture on yield, secondary metabolites, and physiological responses of yerba mate plants, alongside seasonal variations in microclimatic conditions and herbivory attacks. The AFS, featuring Toona ciliata intercropped with yerba mate, provided approximately 45% shade, reducing extreme temperatures and thermal fluctuations. While yerba mate in monoculture exhibited higher photosynthetic capacity, plants in AFS developed morphological adaptations, such as thinner leaves, enhancing performance under shade. Herbivory was initially higher in AFS during spring but equalized between systems later in the season. Secondary metabolite profiles were similar across both systems, indicating no compromise in product quality. Despite distinct microclimatic conditions, crop yields were comparable between systems. These results highlight the capacity of AFS to buffer environmental stress, enhance plant resilience, and maintain productivity, reinforcing its potential as a sustainable cultivation strategy in a changing climate. Adaptive management that integrates seasonal and phenological dynamics could further optimize system performance.