Presentation on theme: "SOIL - Fundamental Concepts ABIOTIC"— Presentation transcript:
1 SOIL - Fundamental Concepts ABIOTIC Prepared byEarl D. LockridgeNational Soil Survey CenterLincoln, NEAmended by: Mr. R
2 SOIL (Know this one)A mixture of mineral matter, organic matter, water, and air that originated from weathered bedrock and has become differentiated with depth into horizonsComposite definition added Geomorphology book
3 SOILMature soil- clearly defined horizons produced by the weathering process. Each layer encroaches on the layer below itPaleosols - ancient soils removed from the zone of soil formation, usually by burial from younger sediments.
4 Major ComponentsMineral matterOrganic matterAirWater
5 SOILComponent definition: Mixture of mineral matter, organic matter, water, and air.Example:Air 25%Mineral Matter 45%Water 25%Organic Matter 5%
6 CLIMATE and TIME –are the most important factors in soil formation bedrock- The igneous, metamorphic, and sedimentary components of the Lithosphere that may exist as mountains, cliffs, or low lying plains
7 Types of Bed RockIgneous- rock from volcanic sources or locations…can be very oldExamples- Granite & Quartz
8 Types of Bed RockSedimentary- rock formed by long term deposition by wind and water. Frequently found in layers.Examples- Sandstone & Shale
9 Types of Bed RockMetamorphic- rock which has been altered by high heat or pressureExamples- slate (altered shale), gneiss (altered granite), diamond (carbon, coal)
10 parent rock- an area of bed rock that is the source of an area of soil
12 Over time the weathered material from the bed rock is covered by both living and dead organic material and a soil horizon develops in a dynamic way.These layer become characteristically differentiated over time due to climatic factors in their environment
13 WeatheringDisintegration and decomposition of rocks by surface processes.Geomorphology book
14 WeatheringMechanical- the physical process of breaking apart rocks (frost/salt wedging, root growth)Chemical- breakdown through chemical alteration (oxidation, hydrolysis, acid inorganic or organic derived from Lichen, fungi, bacteria, mosses and all vascular plant roots)piru.alexandria.ucsb.edu/ ~tierney/TRS/lab6.htm –part of chemical definitdefinition taken form here
15 Factors that Affect Soil Structure Kind of clayAmount of organic matterFreezing and thawingWetting and dryingAction of burrowing organismsGrowth of root systems of plants
16 Important NoteAll of these have a loosening effect on the soil, but they have no effect on aggregate stability
22 The HorizonsO- organic layer of decomposing plant material little mineral contentA- Organic acid design decomposing the parent material giving it a dark color. This is the zone of leaching. Dissolved chemical carried down from the surface. Accessible by plant roots. Most soil organisms found hereOA
23 The HorizonsB- Zone of accumulation. More weathering then C. Parent material is hard to identify. Can be full of clay (more so then the above layers) and impermeable (red brown color common because of oxidation). Nutrients collect in this region-mineral leach up form the parent rock belowBCweb.unbc.ca/~quarles/ nres/soc/ggroup/hp.html
24 The HorizonsC- Slightly weathered parent material (bed rock). Has not undergone leaching and accumulation to the same extent of above layers less oxidation then the B layerD or R- Bed RockBed Rock(Exposed)
42 Pedogenic Pedogenic means pertaining to processes that add, transfer, transform, or remove soil constituents.
43 Physical Properties of Soil Soil textureSoil structureSoil colorBulk density
44 Aspects of Soil Structure The arrangement into aggregates of desirable shape and sizeThe stability of the aggregateThe configuration of the pores
45 Factors that Affect Aggregate Stability Kind of clayChemical elements associated with the clayNature of the products of decomposition or organic matterNature of the microbial population
46 Factors that Affect Soil Structure Kind of clayAmount of organic matterFreezing and thawingWetting and dryingAction of burrowing organismsGrowth of root systems of plants
47 Important NoteAll of these have a loosening effect on the soil, but they have no effect on aggregate stability
48 Major Forms of Iron and Effect on Soil Color Form Chemical Formula ColorFerrous oxide FeO GrayFerric oxide(Hematite) Fe2O3 RedHydrated ferric oxide (Limonite) 2Fe2O3 3H2O Yellow
49 Bulk DensityDetermined by dividing the weight of oven-dry soil in grams by its volume in cubic centimetersThe variation in bulk density is due largely to the difference in total pore space
50 Effects of Bulk Density Engineering propertiesWater movementRooting depth of plants
51 Abiotic soil lab interpretation questions: 1. What soil layers were present at HWWP?2. Which layer was thickest, which was thinnest?3. How does the climate present in this area lead to the development of this type of soil?4. How do you think this type of soil affect the life forms present in the HWWP (plants, animals, bacteria, and fungi)?
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