Clay Minerals—Organic Matter Interactions in Relation to Carbon Stabilization in Soils

Stabilization of C in soil is important for minimizing greenhouse gas emission into the atmosphere and for improving the soil fertility. The physical, chemical, and biological properties of soil greatly influence the C protection capacity. Both the physical and chemical properties of soils are directly or indirectly governed by clay minerals, which are the most reactive soil particles. Apart from the amount of clays, clay types are also very important in protecting soil C. Clay minerals provide both permanent and variable surface charges and different specific surface areas that are crucial to determine the C protection capacity of soils. They form organo–mineral complexes, promote aggregate establishment, and protect soil organic matter against microbial decomposition. This chapter aims to provide an overview of the role of various clay minerals in protecting organic C in soils and highlights the mechanisms of C sequestration by clay minerals.