ABSTRACT
This chapter focuses on carbon storage in primary and secondary organomineral complexes, including the distribution, chemical composition and decomposability of organic carbon associated with differently sized separates. Tiessen and Stewart examined the effects of cultivation on the carbon distribution among size separates from Canadian prairie soils of different textures. The fate of mineral fertilizers, animal manure, crop residues and other organic wastes applied to agricultural soils are also intimately linked with soil organic matter turnover. Soil organic matter encompasses plant, animal and microbial residues in all stages of decay and a diversity of heterogenous organic substances intimately associated with inorganic soil components. Separation of soil into primary organomineral complexes of different size is based on the concept that SOM associated with mineral particles of different size differs in structure and function. Carbohydrates are abundant in plants and are also produced in significant amounts during decomposition.
