Site Characterization Flashcards Preview

IPNI Soil and Water Management > Site Characterization > Flashcards

Flashcards in Site Characterization Deck (14):

O horizon

  • accumulation of organic matter


A horizon

  • mineral horizon at the surface or below the O horizon
    • lost much or all of the original rock structure
    • accumulation of Organic matter
    • often acted upon by man


B horizon

  • Could have any of the following
    • illuviation (deposition) of clay, iron, aluminum, organic matter, carbonates, gypsum and / or silica
    • removal of carbonates
    • residual sesquioxides or coating of sesquioxides reflecting in reddish color of soil
    • clay weathering
    • structural development
    • brittleness


C horizon

  • little affected by soil forming (pedogenic) processes, but not hard bedrock


Parent material

  • the rock, unconsolidated material, or organic matter that forms soil after
    • physical, chemical, or biological pedogenic processes have occurred


Calculate Area of a field

  • Several ways to determine field area
    • break field into squares
    • triangles 1/5 length x width
    • total acres is square feet / 43,560 ft/acre


Determine Slope

  • topographic map, percent of slope is change in landscape elevation in feet for a given distance in feet multiplied by 100.
  • several slopes can be averaged


Characteristics of Well Drained Soils

Characteristics of well-drained soils include:

  • soils are oxidized, iron and manganese are insoluble, soils have color
  • good aeration
  • good avail soil water unless excessively drained leading to drought
  • aerobic microbial processes like nitrification active
  • good root and top growth
  • decomp of most organic materials


Characteristics of Poorly Drained Soils

  • soils reduced, iron / manganese soluble, soil color is grey
  • mottles (areas of color) 
  • poor aeration
  • excessive soil water
  • poor soil structure of peds are not water stable 
  • anaerobic microbial processes like denitrification 
  • poor plant growth unless the plant is aquatic like rice
  • slow decomp of organic materials
    • plant diseases develop


Surface and Subsurface Drainage

  • surface drainage systems
    • ditches
    • grassed waterways
    • levees 
    • precision leveled land
  • subsurface drainage
    • corrugated and PVC pipes
    • mole drains 
    • interceptor drains at base of slope
    • groundwater pumps

subsurface drainage designed to lower water table in soil


Tract of Land

  • legal description
    • Range (R7E)
    • Township (T5N)
      • area of 36 square miles (6 x 6)
        • each divided in 36 sections (square mile, 640 acres)


Limit Land Use and Management

Leaching potential

  • leaching potential varies
  • Septic Filter Fields limited to soils where leaching potential is within certain limits for water renovation and protection of groundwater
  • Biosolids or manure land application sites are limited to areas where both leaching potential and runoff potential is minimal


Limit Land Use and Management

Soil Erosion

  • as erosion potential rises, practices that accentuate erosion should be replaced
    • till vs no till
    • row crop vs pasture
  • land management limited in areas classified as wetlands


Limit Land Use and Management

Soil Drainage Class

  • measure of soils
    • ability to drain water natrually before human modification 
    • the time soil is wet or saturated (presence of water table)