Soil organic matter is the most important component of the ecosystem. As a product of transforming the organic residues under specific conditions it enables us to reflect on the impact rendered by these conditions. In order to be able to perform unique functions in the ecosystem, the organic matter becomes very active in interactions with mineral components. Being widespread in the environment, these compounds play an important role in soil genesis, plant nutrition, migration and accumulation of chemical substances. At present, when the load of heavy metals is augmenting on soil, the consequences of the formation of these compounds in soil requires special attention. New experimental data is needed to provide information about scantily studied soils and complex processes affected by different factors. This book examines current research in the study of soil organic matter.

Concentrations (clarkes) of chemical elements in different components of the environment are indicative of the redistribution of the elements between the main spheres of the planet. Regional clarkes of chemical elements attest to the geochemical diversity of these spheres. The global ecological role of soil is that it, being a product of interaction between biotic and abiotic components of the environment, exerts its own considerable influence on them. This general statement acquires special significance under conditions of constantly growing technogenic impacts on the environment, including the hazardous chemical pollution. Furthermore, the real interaction between chemical elements in all the components of the biosphere is executed by various groups of chemical compounds specific for each of the components of the environment. In this context, the compounds of chemical elements in soils attract special attention.