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Soil science is the study of soil as a natural resource on the surface of the Earth including soil formation, classification and mapping; physical, chemical, biological, and fertility properties of soils; and these properties in relation to the use and management of soils.

The diversity of names of disciplines associated with soil science is related to the various associations concerned. Indeed, engineers, agronomists, chemists, geologists, physical geographers, ecologists, biologists, microbiologists, silviculturists, sanitarians, archaeologists, and specialists in regional planning, all contribute to further knowledge of soils and the advancement of the soil sciences. Soil scientists have raised concerns about how to preserve soil and arable land in a world with a growing population, possible future water crisis, increasing per-capita food consumption, and land degradation.

This is the conceptual perspective of pedology and edaphology, the two main historical branches of soil science. Both branches apply a combination of soil physics, soil chemistry, and soil biology. Many concepts essential to understanding soil come from or have been renewed by individuals not identifiable strictly as soil scientists, like biologists or philosophers.

Soil mapping is the process of classifying soil types and properties in a given area and geo-encoding the information.

In 1998, the World Reference Base for Soil Resources (WRB) replaced the FAO soil classification as the international soil classification system. The FAO soil classification, in turn, borrowed from modern soil classification concepts, including USDA soil taxonomy. A major difference with USDA soil taxonomy is that soil climate is not part of the system, except insofar as climate influences soil profile characteristics.

The earliest known soil classification system comes from China, appearing in the book Yu Gong (5th century BCE), where the soil was divided into three categories and nine classes, depending on its color, texture and hydrology. Contemporaries Friedrich Albert Fallou (the German founder of modern soil science) and Vasily Dokuchaev (the Russian founder of modern soil science) are both credited with being among the first to identify soil as a resource whose distinctness and complexity deserved to be separated conceptually from geology and crop production and treated as a whole. As a founding father of soil science, Fallou has primacy in time, working on the origins of soil before Dokuchaev was born. Dokuchaev's late 19th century soil concept developed in the 20th century to one of soil as earthy material that has been altered by living processes. Further refinement of the soil concept is occurring in view of an appreciation of energy transport and transformation within soil. Accurate to this modern understanding of soil is Nikiforoff's 1959 definition of soil as the "excited skin of the sub aerial part of the Earth's crust".

Academically, soil scientists tend to be drawn to one of five areas of specialization: soil biology, pedology, edaphology, physics, or chemistry. Yet the work specifics are very much dictated by the challenges facing our civilization's desire to sustain the land that supports it, and the distinctions between the sub-disciplines of soil science often blur in the process, with The Critical Zone concept providing a natural framework for cross-disciplinary fundamental research on soil, rock, air, water, and biotic resources at the Earth's surface. Soil science professionals commonly stay current in soil chemistry, soil physics, soil biology, pedology, and applied soil science in related disciplines. One exciting effort drawing in soil scientists in the U.S. as of 2004 is the Illinois Soil Quality Initiative. An internationally accepted soil taxonomy allows uniform communication of soil characteristics and soil functions.

There are also practical applications of soil science that might not be apparent from looking at a published soil survey.

Depression storage capacity, in soil science, is the ability of a particular area of land to retain water in its pits and depressions, thus preventing it from flowing. Soil Survey: Early Concepts of Soil. (html) Soil Survey Manual USDA Handbook 18, Soil Conservation Service.

Quick Facts

• Soil science professionals commonly stay current in soil chemistry, soil physics, soil biology, pedology, and applied soil science in related disciplines.
• Soil Survey: Early Concepts of Soil. (html) Soil Survey Manual USDA Handbook 18, Soil Conservation Service.
• The diversity of names of disciplines associated with soil science is related to the various associations concerned.
• Soil scientists have raised concerns about how to preserve soil and arable land in a world with a growing population, possible future water crisis, increasing per-capita food consumption, and land degradation.
• The FAO soil classification, in turn, borrowed from modern soil classification concepts, including USDA soil taxonomy.

Source material: Wikipedia - "Soil science". Adapted and summarized for DiscoverScroll. Original contributors are credited through the linked Wikipedia article. Read original on Wikipedia. CC BY-SA 4.0. Changes were made from the original.