1 - Soil Physics and Soil Physical Characteristics

Abstract

Soil physics defines, measures, and predicts the physical properties and behavior of the soil, both in its natural state and under the influence of human activities. Soil physics deals specifically with the state and movement of matter, and with the fluxes and transformations of energy in the soil. Practical applications of soil physics aim at the proper management of the soil by means of cultivation, irrigation, drainage, aeration, improvement of soil structure, control of infiltration and evaporation, regulation of soil temperature, and prevention of erosion. Increasingly, the main concern of soil physics has shifted from the laboratory to the field and from a restricted one-dimensional view to an expansive three-dimensional view, interfacing with the domains of sister disciplines such as meteorology and climatology, hydrology, ecology, and geochemistry. This chapter presents a hypothetical soil profile. This is not a “typical” soil, for among the myriad of differing soil types that are recognized by pedologists, no single type can be considered typical. The chapter also discusses the volume and mass relationships among the three phases of the soil and defines some basic parameters that can help to characterize the soil physically.