SS 118 (lec) - M. 1 HO PDF

MODULE1 c) Open system capable of supporting the functions of soil in all ecosystems Introduction to Pedology...

MODULE1 c) Open system capable of supporting the functions of soil in all ecosystems Introduction to Pedology Includes concepts of Biogeochemistry Conceptualizes the factors and processes responsible for the chemical, physical and Two Divergent Views of Soil mineralogical properties of all soils o Including the spatial distribution of Soil as a non-living natural body various soil on the landscape - Organisms are not part of the soil but temporary occupants - Only when they die that they become part of 2. Soil Classification the soil the categorization of soils into groups at varying levels of generalization based on their physical, mineralogical, and chemical Soil as a living natural body properties. The objectives of soil classification include: - Organisms living in it are considered part of o Organization of knowledge the soil since they also affect the non-living o Ease in remembering properties components of the soil. o Clearer understanding of relationships o Ease of technology transfer and communication Two Principal Approaches in the Study of Soil Pedogenetic Approach 3. Soil Morphology - Focuses on the genesis of the soil in the Encompasses: landscape o Color, physical structure, chemical and - Studies the soil and its properties as it appears mineralogical properties of soil material in the natural environment. o Spatial association of materials in soil horizons Ecological Approach o The temperature and moisture dynamics - deals with the dynamics (Fiedler et al., 2002) of soil in situ and functions of the soil. - includes the classical edaphological approach which emphasizes the soil as a medium for A branch of soil science that deals with the: plant growth. Soil Formation Soil Genesis Soil Morphology Pedology Defined Soil Classification Pedology was derived from two Greek Words: Description of Soil Properties o Pedos – ground/soil or earth o logos – science/study o Originally formed as Russian, pedologiya Pedology Cover a Range of Ideas and Concepts The study of soil in its natural position (Joeffe, 1936) Definition of Soil A collective term used to refer to the Soil Profiles and Pedons combination of two phases of soil science Soil-forming factors 1. Soil Genesis and Classification Pedogenic Processes 2. Soil morphology, survey and mapping, and Soil Classification interpretations Soil Geography and Mapping Soil-Landscape Relationship Subdivisions of Pedology Historical Review of the Concept of Soil 1. Soil Genesis Century-old science that dealt with soil in three Theophrastus - 371-286 B.C. conceptual phases: a) Geologic entity Gave the “edaphos” term for the soil. b) Product of factors and processes of soil Described soil properties that affect growth. formation Cato - 234-149 B.C. Developed a classification system of arable Summary of the Historical Review of the Concept of soils. the Soil Emphasized the suitability of soils for farming. Roman thinkers started land evaluation for tax purposes based of smell, taste, and other soil properties J. Von Liebig - 1803-1873 Established agricultural chemistry Formulated the mineral theory of plant nutrition –The Law of Minimum Henry Darcy - 1803-1929 Developed the key law in Soil Physics (Darcy’s Law) that describes water flow in soils Joseph Henry Gilbert - 1817-1901 Established first systematic long-term field Soil Profile VS Pedon fertilizer experiment in the world-famous Rothamsted Experimental Station (started in Pedon 1843) 3-D unit that represents the entire soil body Smallest volume of soil that shows all the characteristic properties of a particular soil. F.A. Fallou - 1794-1877 Typically represents 10-100m2 of surface area Simonson and Gardner (1960) who proposed Founder of Soil Science the pedon concept compared it to the cell in In his book “Pedology of General and Special biological systems. Soil Science” (1862), he argued for the recognition of Soil Science as an independent Soil Profile natural science He showed that soil layers have to be A 2-D body used as the standard unit of soil evaluated to understand the soil description Vertical section of the soil from the surface down the bedrock V.V. Dokuchaev - 1846-1903 Divided with horizontal layers called the horizons Father of Modern Soil Science One side of a pedon Discussed the factors of soil formation and he Typically, 1m x 1m x 1.5 m introduced the ABC horizon nomenclature system Influenced by the writings of Fallou. Soil and Landscape Landscape E.W. Hilgard - 1833-1893 Three-dimensional section of the Earth’s surface with specific pattern of: One of the first to apply soil science to solve o Topography problems in agriculture and is considered the o Rocks “Father of American Soil Science” o Soil o Water o Flora Hans Jenny - 1899-1992 o Fauna In 1941 published “Factors of Soil Formation” s = f (cl, o, r, p, t,...) E. Schlichting (1923-1988) Professor at the University of Hohenheim in Stuttgart Pioneered the approach of considering the soil always as part of the landscape. proposed that soils in different positions in the landscape (or catena) exchange materials through transport processes. Thus, this could be compared to the transfer processes between horizons in a soil profile. Landscape pedology is an emerging science focusing on soil as part of the landscape particularly on the variability of soil properties at the landscape scale (1- 10km) (Sommer, 2006). Ecosystem Natural system consisting of biosystem interacting with the geosystem. Two Major Types of Ecosystems Aquatic Ecosystem Any water-based environment in which plants and animals interact with the chemical and physical features of the aquatic environment. Terrestrial Ecosystem land-based community of organisms and the interactions of biotic and abiotic components in a given area. All the terrestrial ecosystem types are linked by the soil.