Soil Science - Definition and Approaches PDF

## 1.2 Soil Science - Definition and Approaches 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 a...

## 1.2 Soil Science - Definition and Approaches 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. Sometimes, terms which refer to branches of soil science, such as pedology (formation, chemistry, morphology) and edaphology (influence of soil on organisms, especially plants), are used as synonymous with soil science. One treats soil as a natural body, weathered and synthesized product immature (Pedology) while other treats soil as a medium for plant growth (Edaphology). The two basic approaches - Pedological and Edaphological, are used in studying the soils. ### (i) Pedological Approach The origin of the soil, its classification, and its description are examined in pedology (from the Greek word *pedon*, means soil or earth). Pedology is the study of the soil as a natural body and does not focus primarily on the soil's immediate practical utilization. A pedologist studies, examines, and classifies soils as they occur in their natural environment. ### (ii) Edaphological Approach Edaphology (from the Greek word *edaphos*, which means soil or ground) is the study of soil from the standpoint of higher plants. Edaphologists consider the various properties of soils in relation to plant production. They are practical and have the production of food and fiber as their ultimate goal. To achieve that goal, edaphologists must be a scientist to determine the reasons for variation in the productivity of soils and find means of conserving and improving productivity. ## Soil Science has major six well defined and developed disciplines: 1. **Soil Fertility:** Deals with the nutrient supplying capacity of soils. 2. **Soil Chemistry:** Studies of soil chemical properties and the chemical reactions. 3. **Soil Physics:** Studies of soil physical properties. 4. **Soil biology:** Deals with the soil organisms and their roles in soil fertility. 5. **Soil Conservation:** Deals with protect and conserve the soils. 6. **Soil Pedology:** Deals with the soil genesis, soil survey, mapping and classification. ## International Union of Soil Sciences highlighted following key facts of soils: - It can take more than 1000 years to form a centimeter of topsoil. - There are over 10000 different types of soil exist worldwide. - A handful of soil can contain billions of soil microorganisms. There are more individual organisms in a handful of fertile soil than world's human population. - Soil is one of the most complicated biological materials on our planet. - Soil stores 10% of world's CO2 emissions. Soil carbon is the largest global carbon pool.