Ancestral roots: Exploring microbial communities in traditional agroecosystems for sustainable agriculture

Scientific research on microorganisms associated with crops in agroecosystems has revealed how modern practices disrupt microbial communities, compromising their vital ecological and nutritional functions, including their roles in plant adaptation to biotic and abiotic stresses. For this reason, there is an urgent need to understand the beneficial functions of microorganisms in low-input or natural soils and their application for transitioning to more sustainable agricultural practices. We propose that traditional agroecosystems are a promising study model since productivity is achieved through ancestral practices, maintaining greater diversity and functions of microorganisms associated with crops. In this review, we explore traditional agroecosystems worldwide based on the Globally Important Agricultural Heritage Systems (GIAHS), selecting three representative agroecosystems: 1) Rice paddy in Asia & Pacific; 2) Oasis Agroecosystem in the Near East and North Africa; and 3) Milpa in Latin America and the Caribbean. Next, through a systematic qualitative approach, we examine the progress in studying the structure and function of the plant-associated microbiome of the selected traditional agroecosystems. We discuss how microbial communities are influenced by ancestral agricultural practices, impacting ecosystem services such as nitrogen fixation and mineralization, phosphorus solubilization and mineralization, and tolerance to biotic and abiotic stresses. Finally, we discuss perspectives for biotechnological applications and basic research in traditional agroecosystems toward sustainable agriculture, emphasizing the participation and compensation of local farmers.