History of soil science

The early concepts of soil were based on ideas developed by a German chemist, Justus von Liebig (1803–1873), and modified and refined by agricultural scientists who worked on samples of soil in laboratories, greenhouses, and on small field plots.

The early geologists generally accepted the balance-sheet theory of soil fertility and applied it within the framework of their own discipline.

They conceived soils as mainly the weathering products of geologic formations, defined by landform and lithologic composition.

Those published from 1910 to 1920 gradually added greater refinements and recognized more soil features but retained fundamentally geological concepts.

This concept required that all properties of soils be considered collectively in terms of a completely integrated natural body.

Although a distinction between these sets of processes is useful for some purposes, rock and mineral weathering and soil formation are commonly indistinguishable.

The morphology of a soil came to be described by ranges of properties deviating from a central concept instead of by a single "typical" profile.

In spite of this, Marbut's work reveals his personal understanding of the contributions of geology to soil science.

Concepts changed with increased emphasis on predicting crop yields for each kind of soil shown on the maps.

During the 1930s, soil formation was explained in terms of loosely conceived processes, such as "podzolization", "laterization", and "calcification".

As a consequence, the formation of soil has come to be treated as the aggregate of many interrelated physical, chemical, and biological processes.

The focus of attention also has shifted from the study of gross attributes of the whole soil to the co-varying detail of individual parts, including grain-to-grain relationships.

Both systems reflected the concepts and theories of soil genesis of the time, which were themselves predominantly qualitative in character.

[5][6] There is now ample evidence to support Darwin's conclusions, and in many areas biota that burrow in soil are major agents of pedogenesis.

[11] Flaws in the established paradigm were made apparent in 1999[12] when soil models could not accommodate the large charcoal component present in Chernozems.

In 2016[13] soil science textbooks began addressing the need to abandon long-accepted, but now outdated, concepts.

[14][15] As of 2021, few[16] yet understand that the classic textbook theory of soil organic matter accumulation "has been proven mostly false".