Geochemical History of Carbon on the Planet: Implications for Soil Carbon Studies

This chapter aims to elucidate the geochemical history of carbon on the planet and to reveal the role of soil cover in the global carbon cycling. It considers some methodical issues of soil carbon studies. Carbon, together with oxygen and nitrogen shares the third to fifth place in abundance in the Universe, and ranks among the second ten of the elements composing our planet. Carbon compounds are found in cosmic space and in composition of meteorites and comets; the atmosphere of such planets as Venus and Mars is almost completely composed of CO₂. Biotic component of carbon cycle is "responsible" not only for the appearance of oxygen in the atmosphere and the formation of the immense reserves of carbon in the lithosphere. Considering the problem of carbon cycling in the biosphere, A.B. Ronov pointed to the importance of geological processes of carbon exchange between the biosphere and the interior of the planet.