Book excerpt: The understanding of plant-soil interactions in acid soils is important for improved food production in many parts of the world. The context of the book touches on basic and applied aspects of the physics, chemistry and biology of acid soils and their effect on growth of plants. It contains a large section on management of acid soils for plant (food) production and on socioeconomic aspects of management of acid soils. This is important because a large portion of the world's acid soils occurs in less developed countries. Plant-Soil Interactions at Low pH: Principles and Management contains a substantial number of papers, including nine invited reviews, presented at the Third International Symposium of Plant-Soil Interactions at Low pH. The major themes include chemistry and physics of acid soils, microbial and faunal activity in acid soils, mechanisms of acid tolerance of plants, selection and breeding of acid-tolerant plants, diagnosis and correction of acid soil infertility, socioeconomic aspects of acid soil management and management systems for agriculture, horticulture and forestry on acid soils.