Powerpoint Presentation to depict factors affecting soil formations
Five factors involved in soil formation There are five primary factors that affect the process of soil formation and development. Parent material—type of rock material the soil is formed from. Climate—temperature and moisture characteristics of the area in which the soil was formed. Living organisms—the organisms, including plant material, that live within the soil. Time or weathering—age of the soil and its climate
SOIL FORMATION Soil formation is the combined effect of physical, chemical, and biological processes on soil parent material. Soil genesis involves processes that develop layers or horizons in the soil profile. These processes involve additions, losses, transformations and translocations of material that compose the soil. The weathering of bedrock produces the parent material that soils form from.
Parent material Parent materials are formed by the disintegration and decomposition of rock. They are classified according to the way they were moved and scattered. Many soils have been formed from material originally moved by glaciers. Soils of glacial origin are classified as follows: TYPES OF PARENT MATERIAL 1. Loess—occurred from the blowing of the soil after the glaciers melted and dried. 2. Outwash—occurred when the glaciers melted. The melt waters carried the gravelly materials away to be deposited below the glacial ridges. Sandy outwash was carried further downstream and the finer materials, silt and clay, were deposited in lakebeds or slow moving water along streams.
TYPES OF PARENTS MATERIAL 3. Glacial till—have not been layered from the effects of wind or water as the other two types of glacial soils. It often contains a variety of sizes of soil particles. Pebbles and various sizes of boulders are common in till.. Some soils are formed as a result of recent sediments deposited by streams as they flood. It is referred to as alluvium. Alluvium is generally a water-borne material deposited on bottomlands
TYPES OF PARENT MATERIAL Bedrock —shale, sandstone, or limestone bedrock; weathered bedrock can provide soil parent materia Organic matter —occur where formerly shallow ponds supported swamp vegetation. The wet conditions slowed decay of the dead plants so that organic matter could accumulate. The two types of organic soils are referred to as peat and muck. Muck is more decomposed than peat.
Parent material effect The parent material of a soil determines the original supply of those nutrient elements that are released by weathering and influences the balance between nutrient loss and retention. Organic acids and exudates produced by microorganisms and plants enhance the weathering of minerals and the release of nutrients
topography effect Topography has a strong influence on soil development. Soils on the side of hills tend to be shallow, due to erosional losses. Soils on the tops of hills tend to be deep, but lighter in color, due to downward leaching losses. Soils in the valleys tend to be deeper, darker, and contain more horizons. This is due to increased material deposition from hillside erosion, material accumulation from downward leaching from the tops of hills, and the collection of greater quantities of water in the low lying areas.
Climate effects Climate: Temperature and moisture influence the speed of chemical reactions, which in turn help control how fast rocks weather and dead organisms decompose. Soils develop faster in warm, moist climates and slowest in cold or arid ones. Rainfall is one of the most important climate factors in soil formation.
Living organisms effect Living organisms affects soil formation by producing or contributing to humus production. Plants, animals, micro-organisms, and humans affect soil formation. Animals and microorganisms mix soils and form burrows and pores. Plant roots open channels in the soils. Organisms decompose these leaves and mix them with the upper part of the soil.