Download Soil Formation and Profile Development and more Slides Geochemistry in PDF only on Docsity! Semi Regional – Lag Sampling Swept from the surface Sieved to 2–6 mm Data may be normalised to Fe content Sample grids at 500m by 500m have been used Docsity.com Data From: Reimann, Clemens (2000): Kola-Atlas, Humus, PANGAEA, doi:10.1594/PANGAEA.56279 Regional Soil Data - As in humus Anthropogenic Control Docsity.com Soil Formation Parent Material Minerals and organic materials present during it's formation. Materials from volcanoes, sediment transported by wind, water or glaciers or minerals left behind by drying lakes are good examples of parent materials. Climate Parent material is broken down into smaller pieces by a process called weathering. Cycles of freezing and thawing, wetting and drying, and the frequency of these occurrences coupled with average temperature and moisture levels of region play an important role in soil formation. These smaller pieces are known as (sand, silt and clay), clay being the smallest size. Living Organisms Both plants and animals help to create a soil. As they die, organic matter incorporates with the weathered parent material and becomes part of the soil. Living animals such as moles, earthworms, bacteria, fungi and nematodes are all busy moving through or digesting food found in the soil. All of these actions mix and enrich the soil. Topography Topography is the hilliness, flatness, or amount of slope of the land. Soils vary with topography primarily because of the influence of moisture and erosion. In many areas, moist, poorly drained soils are located in low areas, and depressions of the land. In contract, soils in sloping areas can be drier and well drained. These soils tend to be moderately and well developed. Erosion can remove all or part of the topsoil and subsoil, leaving weakly developed soil. Time It may take hundreds of years to form one inch of soil from parent material. Only the top few inches are productive in the sense of being able to sustain plant growth. This is why soil conservation is so important. Docsity.com Always Occur: Weathering of parent material Addition and partial decomposition of organic matter Formation of structural units (Profile) Depending on Environment Leaching and acidification Clay eluviation (washing of clay from upper horizons) Podzolisation (transport of DOC and Fe & Al from upper h) Leaching of Si relative to Fe and Al Reduction (ferric to ferrous) Salinisation Erosion Soil Formation Docsity.com Soil development is initiated by the weathering of the bedrock and the incorporation of organic matter. These processes produce: dissolved matter (bases, silicic acid, Fe, Al etc.); dispersed colloidal particles (e.g. silica, etc.): hydroxyls (Fe, Al, etc.): organic complexes; and, fine particulate matter (clay, clay-sized particles, etc.) Profile Development Docsity.com
