Agroecological drivers of aflatoxin contamination in maize-based systems: a review

Aflatoxin contamination of maize remains a global food safety and public health challenge, particularly because it is a dietary staple food and feed ingredient produced across diverse agroecological zones. Although numerous mitigation strategies have been developed, contamination levels remain variable. This reflects complex interactions among climate, soil properties, crop management practices, plant physiological stress and rhizosphere microbial communities. This review synthesizes evidence on key agroecological drivers of aflatoxin contamination in maize, highlighting climate variability, soil properties, crop and nutrient management, cropping systems, and rhizosphere microbial communities as primary determinants. We examine how these factors influence Aspergillus population dynamics, microbial interactions and aflatoxin biosynthesis across contrasting production environments. Evidence synthesized in this review indicates that inconsistent outcomes of existing management including biological control strategies largely arise from insufficient consideration of soil-plant-microbe interactions and spatial heterogeneity. We identify climatic stress, soil properties and crop management strategies as the dominant determinants of aflatoxin risk, acting through biological mediators such as plant physiological status, rhizosphere microbial communities and fungal population. The review argues that effective and scalable aflatoxin mitigation requires integrated, context-specific and systems-based approaches. We conclude that incorporating agroecological heterogeneity into research design, predictive models and management frameworks is essential for improving risk prediction and developing aflatoxin control strategies in maize-based cropping systems.