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Rangeland Soils. UDSI-BLM. UDSI-BLM (Bob Wick). UDSI-BLM. REM 151 Rangeland Principles. What is Soil?. Geologic definition : Loose surface of the earth as distinguished from solid bedrock (support of plant life not required). http://soils.cals.uidaho.edu.
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Rangeland Soils UDSI-BLM UDSI-BLM (Bob Wick) UDSI-BLM REM 151 Rangeland Principles
What is Soil? • Geologic definition: Loose surface of the earth as distinguished from solid bedrock (support of plant life not required). http://soils.cals.uidaho.edu http://soils.usda.gov/education/resources/k_12/tools.html
What is Soil? • Traditional definition: Material which nourishes and supports growing plants (includes rocks, water, snow, air). NRCS-USDA (Catherine Ulitsky) http://soils.usda.gov/education/resources/k_12/tools.html
What is Soil? • Component definition: Mixture of mineral matter, organic matter, water, and air. Air 25% Mineral Matter 45% Water 25% • Soil Components: mixture of mineral matter, organic matter*, water, and air • * Land managers can only manage for the organic matter. Organic Matter 5% http://soils.usda.gov/education/resources/k_12/tools.html
Soil Forming Processes • Translocations – movement of soil particles • Transformations – chemical and physical changes • Additions – organic and inorganic particles added • Losses – removal of particles from soil http://soils.cals.uidaho.edu
Soil Formation Climate CLORPT • 5 Force that Create Soils = CLORPT • CL = Climate • O = Organic Matter • R = Relief • P = Parent Material • T = Time Organisms SOIL Relief Parent Material Time
Soil Formation Climate CLORPT • High precipitation overtime increases: • Acidity • Leaching • Nitrogen content • Clay content SOIL • High temperature overtime increases: • Increase leaching of bases (Ca, Mb, Na, K) • Decreases nitrogen • Low organic matter at low and high temperature
Soil Formation Climate A productive soil is a living soil Organisms SOIL • Nitrogen fixation • Decomposition • Mixing soil & aeration • Removing and changing nutrients • Holding moisture
Soil Formation Climate Organisms SOIL Relief • Topography • Accumulation of soil on landscape • Amount of water that enters soil
Soil Formation Climate CLORPT Organisms SOIL Relief Parent Material • Texture (i.e., sand, silt, clay) • Mineral nutrients (i.e., K, P, Na)
Soil Texture Sand = 0.05-2.0mm Silt = 0.002-0.05mm Clay = < 0.002 mm • Drainage • Water holding capacity • Aeration • Susceptibility to erosion • Organic matter content
Soil Structure http://soils.usda.gov/education/resources/k_12/tools.html
Soil Color • Indicator of different soil types • Indicator of certain physical and chemical characteristics • Due to humus content and chemical nature of the iron compounds present in the soil
Major Forms of Iron and Effect on Soil Color FormChemical FormulaColor Ferrous oxide FeO Gray Ferric oxide (Hematite) Fe2O3 Red Hydrated ferric oxide (Limonite) 2Fe2O33H2O Yellow
Soil Formation Climate CLORPT Organisms SOIL Relief Parent Material Time
Climate Organisms Vegetation SOIL Relief Parent Material Time K. Launchbaugh
Soil Maps Soil Series: a group of soils that are similar in texture and profile. Soil Map Units: grouping of soils that occur together, often based on geomorphology.
Soil Maps • Soils affect the type of plants that grow on the land. • Therefore, soil maps usually form the basis for maps of ecological sites.
Soils →→ Ecological Sites Soil affects the type of plants that grow on the land. Ecological Site = a distinctive kind of land producing a distinctive kind and amount of vegetation Therefore, soil maps forms the basis for maps of ecological sites. USDI-BLM (Greg Shine)
Ecological Site • A recognizable land type: • Specific physical characteristics • soils, climate, hydrology, geology, topography • Distinctive kind and amount of amount of vegetation • Respond similarly to management actions and natural disturbances.
(Example 1) Ecological sites vary in kind and amount of vegetation
Specific physical characteristics • soils, climate, hydrology, geology, topography • Distinctive kind and amount of amount of vegetation • Respond similarly to management actions and natural disturbances. Ecological Potential Ecosystem Dynamics
Ecological Potential Ecosystem Dynamics
Ecological Potential Ecosystem Dynamics
Rangeland Soils UDSI-BLM UDSI-BLM (Bob Wick) UDSI-BLM REM 151 Rangeland Principles