Agroecosystems represent the dynamic interaction between agricultural activities and the environment. Below-ground interactions in agroecosystems involve a complex network of interactions among soul organisms, plant roots and the physical and chemical properties of the soil. These interactions are crucial for plant health, nutrient cycling, soil structure and overall ecosystem functioning. Plant roots absorb water and nutrients while releasing root exudates that influence microbial communities. Symbiotic relationships, like those with mycorrhizal fungi and nitrogen-fixing bacteria, enhance nutrient uptake and soil fertility. Soil fauna, such as earthworms and nematoes, contribute to nutrient cycling and soil structure. Decomposers break down organic matter, releasing nutrients back into the soil. This book contains some path-breaking studies in the field of below-ground interactions in agroecosystems. It traces the progress of this field and highlights some of its key concepts and applications. Through this book, we attempt to further enlighten the readers about this discipline.