Definition of Soil Science

   

Soil science is a scientific discipline dedicated to the comprehensive study of soil as a natural resource, primarily focusing on its properties and characteristics in relation to plant growth. This field encompasses the investigation of soil composition, structure, fertility, and the dynamic interactions between soil and plants. Soil scientists aim to understand the physical, chemical, and biological processes occurring within the soil environment, with the ultimate goal of enhancing sustainable and productive land use for agriculture and other ecological purposes.

Branches of Soil Science

The field of soil science is broad and encompasses various branches, each focusing on different aspects of soil and its management. The branches of soil science, as defined in the Glossary of Soil Science Terms (Soil Science Society of America, 1987), include:

A.    Soil Genesis and Classification (Pedology): This branch investigates the weathering of rocks and minerals and the processes leading to soil formation. It also involves systematically categorising soils based on their characteristics.

B. Soil Survey: Soil survey involves the systematic examination of soils in both the field and laboratory. This includes describing, classifying, mapping, and interpreting soils based on their suitability for different land management systems.

C. Soil Chemistry: This branch explores the chemical composition, properties, and processes occurring in the soil.

D. Soil Fertility: Soil fertility is concerned with a soil's capacity to provide essential nutrients for plant growth.

E. Soil Physics: Soil physics focuses on the mechanical behaviour of soil, emphasising physical properties and the movement of matter (especially water) and energy in the soil.

F. Soil Salinity: This branch addresses the presence of excess soluble salts in the soil, including their reclamation and management for saline agriculture.

G. Soil Mineralogy: Soil mineralogy examines both primary and secondary soil minerals and their contributions to soil chemistry, physics, fertility, and biology, as well as their relationship to soil formation.

H. Soil Biology: Soil biology studies organisms inhabiting the soil and their functions and activities.

I. Soil Conservation: Soil conservation involves safeguarding the soil from physical loss through erosion (by wind and water) or chemical deterioration. It encompasses a combination of management and land conservation practices.