Soil Science

a natural science that treats of the composition, properties, origin, development, geographic distribution, and rational use of soil. It studies soil as a natural body, as a means of production, and as an object of work. Its most important branches are the genesis of soils; geochemistry; the physical, colloidal, and biological chemistry of soils; and the biology, physics, hydrology, and geography of soils.

The scientific study of soils began in the late 18th century. Around 1800 the German scientist A. Thaer advanced the humus theory of plant nutrition, which stimulated an intensive investigation of humus. J. Liebig’s theory of mineral nutrition of plants, which succeeded the humus theory in the 1840’s, promoted chemical research on soil and gave rise to the agrogeologi-cal approach in the late 19th century. Expounded by several German scientists, among them F. Fallou and F. von Richt-hofen, the agrogeological theory treated soil as a geological formation, a weathering product, without taking the biological processes into account. Consequently, it could not give a correct idea of the nature of soil, although advances were made on such questions as the mineral, chemical, and granulometric composition of soil.

Genetic soil science originated in Russia in the second half of the 19th century, with the publication of V. V. Dokuchaev’s monograph Russian Chernozem in 1883. In this work Dokuchaev formulated the main principle of his theory—that soil is an independent natural organomineral body formed from the surface layers of rock, from which it differs qualitatively, as a result of the action of living organisms (including microorganisms) on the layers under certain climatic conditions. Regarding fertility as an inherent property of soil, Dokuchaev advanced and substantiated the idea of factors of soil formation—parent material, climate, vegetation, topography, and age of the land (later, man’s economic activity and other factors completed the list). He also showed the need to study soil from the standpoint of its origin and its close relationship to the surrounding conditions (the geographic approach in soil science). P. A. Kostychev, a contemporary of Dokuchaev, played a significant role in the creation of pedology. He developed the agronomic approach by investigating the relations between soil, vegetation, and fertility. The agronomic approach was later elaborated by V. R. Vil’iams.

Dokuchaev’s approach to soil science was the basis of efforts to control drought and evaluate land. His students and followers —N. M. Sibirtsev, F. Iu. Levinson-Lessing, P. A. Zemiatchen-skii, G. N. Vysotskii, V. I. Vernadskii, and K. D. Glinka—also made important contributions to the advancement of genetic soil science. The work of these investigators reflected mainly the geographic approach in soil science—a comparative analysis of the structure of the soil profile in relation to the factors of soil formation.

A new approach that might be called the chemical school arose in the early 20th century. It was introduced by K. K. Gedroits, who worked out the fundamentals of colloidal soil chemistry. The study of soil colloids proved to be the key to understanding the nature of the diverse (physical, chemical, biological) processes underlying soil formation and the present-day state of the soil. The founding of biogeochemistry by V. I. Vernadskii in the 1920’s gave rise to the biogeochemical approach —the study of the role of living organisms in the soil and their function in soil formation. Other branches of soil science emerged in the 1930’s, such as the physical chemistry, physics, mineralogy, and microbiology of soils. Among those who influenced the development of soil science in this period and later were L. I. Prasolov, B. B. Polynov, I. V. Tiurin, I. P. Gerasimov, I. N. Antipov-Karataev, V. A. Kovda, E. N. Ivanova, A. A. Rode, M. M. Kononova, N. N. Rozov, N. A. Kachinskii, S. V. Zonn, V. R. Volobuev, M. A. Glazovskaia, D. G. Vilen-skii, and E. N. Mishustin.

The synthesis of the geographic, chemical, and biogeochemical approaches led to the present conception of soil as a natural system consisting of four main parts—solid, liquid, gaseous, and animate—in which the processes of conversion and movement of matter and energy are continuously taking place and are constantly interacting with one another. The presence of living organisms makes soil one of the bioinert bodies of the biosphere. The theory of soil fertility and soil classification and diagnosis have been elaborated on this basis. The main tasks of modern soil science are the further study of the genesis of soils and, especially, of the dynamics of the processes that take place in natural and cultivated soils and link animate and inanimate nature. These processes are extensively studied in soil science, which accounts for the great importance of soil science in solving problems connected with the conservation of nature and rational use of natural resources.

Dokuchaev’s ideas greatly influenced the development of soil science abroad. International Congresses of soil scientists played a major role in disseminating Dokuchaev’s findings, especially the First and Second congresses, held in the United States in 1927 and in the USSR in 1930. (The Tenth Congress was held in the USSR in 1974.) Genetic soil science was accepted by the scientists of all countries, and it served as the basis for the founding of schools of soil science in the 1930’s and 1940’s in the USA (C. Marbut, E. Hilgard), Germany (E. Ramann, E. Mit-scherlich), the Netherlands (D. Hissink), Great Britain (E. Russell and W. Ogg), Rumania (G. Murgoci), Yugoslavia (V. Neuge-bauer and M. Gračanin), and Sweden (O. Tamm).

Field, expeditionary, and permanent-station methods, laboratory (physical, physicochemical, chemical, microscopic, roent-genographic, radioisotopic, spectroscopic) methods, and comparative geographic and cartographic methods are widely used in soil science. Soil science is closely related to climatology, geomorphology, mineralogy, petrography, microbiology, plant physiology, chemistry, physics, and other sciences.

Soil science is particularly important in agriculture, where it helps solve problems connected with increasing soil fertility, using fertilizers, carrying out reclamation projects (irrigation, drainage, liming, gypsuming), and controlling erosion. Soil maps are essential for the development of agrochemical, agrotechnical, and reclamation proposals and for land evaluation. The achievements of soil science are also used in building roads and engineering works.

The chief research centers for soil science in the USSR are the V. V. Dokuchaev Soil Institute and Institute of Agricultural Chemistry and Soil Science, founded in 1970 under the auspices of the Academy of Sciences of the USSR. Soil institutes have been established in almost all the Union republics, and many universities, as well as all higher schools of agriculture and many higher wood-technology schools, have soil science subdepart-ments. Abroad, research is conducted by the Department of Agriculture, the Soil Conservation Service, and agricultural departments of universities in the USA, by the Rothamsted Experimental Station and the Macaulay Institute for Soil Research in Great Britain, by institutes of soil science in the Federal Republic of Germany (FRG), by the Institute of Forestry in Sweden, by the Institute of Agronomical Research and the Institute of Biological Soil Science in France, and by institutes of soil science in the German Democratic Republic (GDR), Poland, Czechoslovakia, Rumania, Bulgaria, and Hungary.

Among the leading journals devoted to soil science are Pochvovedenie (Soil Science) in the USSR (since 1899); Soil Science (Baltimore, since 1916) and Soil Science Society of America: Proceedings(Madison, since 1936) in the USA; the Journal of Soil Science (Edinburgh, since 1949) in Great Britain; Zeitschrift für Pflanzenernaehrung und Bodenkunde (Weinheim, since 1922) in the GDR; the Canadian Journal of Soil Science (Ottawa, since 1921) in Canada; the Indian Journal of Agricultural Science (New Delhi, since 1931) in India; and Annales agronomiques (Paris, since 1875) in France.

In 1958, Soviet soil scientists formed the All-Union Society of Soil Scientists, which is part of the International Society of Soil Sciences, founded in 1924. National societies of soil scientists are found in the USA, Canada, Great Britain, the Federal Republic of Germany, the German Democratic Republic, France, Rumania, Yugoslavia, Czechoslovakia, Japan, Australia, India, New Zealand, Venezuela, and Argentina.