Soil Science

Soil Science is a branch of environmental science focusing on 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.

Overview

Soil scientists have two main branches of study: pedology and edaphology. Pedology focuses on the formation, morphology, and classification of soils as a component of natural landscapes. Edaphology studies the way soils influence plants, fungi, and other living organisms. Both branches apply principles from a wide range of sciences, including biology, physics, and chemistry, to understand the behavior of soils in natural and managed environments.

Soil Formation

Soil formation, or pedogenesis, is the process by which soils are created. The primary factors influencing soil formation include parent material, time, climate, organisms, and topography. These factors interact through various soil-forming processes such as weathering, leaching, and microbial decomposition, which alter the soil's physical and chemical properties over time.

Soil Classification and Mapping

Soil classification involves categorizing soils based on their properties and behaviors into a systematic framework. The most widely used system in the world is the Soil Taxonomy provided by the United States Department of Agriculture (USDA). Soil mapping, on the other hand, is the process of creating maps that show the distribution of different soil types across the landscape.

Soil Properties

Soil properties are divided into physical, chemical, and biological categories:

• Physical properties include texture, structure, and porosity, which affect water and air movement, root growth, and other processes.
• Chemical properties involve nutrient availability, pH, and cation-exchange capacity, which influence soil fertility and plant growth.
• Biological properties concern the organisms living in the soil, including microorganisms, insects, and larger animals, all of which play roles in nutrient cycling and organic matter decomposition.

Soil Use and Management

Understanding soil properties and behaviors helps in the management of soils for agriculture, forestry, urban development, and ecological restoration. Proper soil management aims to maintain or enhance soil fertility while minimizing soil degradation and pollution.

Challenges in Soil Science

Soil scientists face several challenges such as soil erosion, contamination, salinization, and loss of biodiversity. Addressing these issues often requires interdisciplinary approaches and collaboration among scientists, land managers, policymakers, and the public.

Professional Organizations

Several professional organizations support soil science research and education, including the Soil Science Society of America (SSSA) and the International Union of Soil Sciences (IUSS).

See Also

• Agronomy
• Hydrology
• Environmental science
• Sustainable agriculture