1. soil functions
    medium for plant growth, regulator of water supplies, habitat for organisms/biota, public health, recycling/storage of raw minerals
  2. 4 soil processes
    additions (input organic matter), losses (erosion, decomposition), translocations (movement down), transformation (chemical/physical modifications of elements in soil)
  3. weathering
    chemical/physical alteration and reorganization of rocks and minerals 
  4. 5 soil factors
    parent material (original material), climate (temp/moisture), organisms/biota(vegetation, macro, micro) relief/topography (altitude, slope) time (controls extent of other factors)
  5. pedogenesis
    the process of soil formation as the result of the combination of soil forming factors and processes
  6. sources of parent material
    residual (formed in place from rocks and minerals), alluvial (deposited by rivers/streams), marine (oceans), eolian (wind), glacial (ice)
  7. Florida's parent material.
    sandy marine/alluvial sediments which derived from clayey, silty sands
  8. rain & temp on soil formation
    • water increases weathering rates and translocations
    • heat increases rates of physicochemical processes
  9. soils horizons
    O (above mineral soil),A (surface mineral, accumulation of OM, weathered, elluvial, p sub),E (zone of loss),B (zone of accumulation of clays, OM, salts, iron, t,h,w,g sub),C (resembles parent material),R (bedrock)
  10. subordinate
    a (sapric highly decomposed),e (hemic mod),i (fibric slightly),g (gleying-wet, low oxygen),h (OM),p (disturbed, plowed),t (clay),w (weak)
  11. munsell soil color components
    • hue-proportions of red and yellow
    • value-reflected light
    • chroma-strength of color
  12. 3 particle size
    • sand 2.0-0.05mm
    • silt 0.05-0.002mm
    • clay less than 0.002mm
  13. primary and secondary minerals
    • primary dominate sand & silt, not ractive
    • secondary dominate clay, very reactive
  14. total porosity
    the total volume of pore space in a soil, indicates max volume of water and gasses a soil can hold (finer-textured soils have greater TP)
  15. pore size distribution
    large particles yield large pores
  16. Stokes' Law
    • settling velocity of particles in a fluid
    • V=KD2 (K=11,241)
  17. soil bulk density & particle density
    • BD=mass OD soil/volume soilds+pores
    • range 1.0-1.6 g/cm3
    • 1-5& OM

    PD=2.65g/cm3 (no pores)
  18. important
    • OM increases porosity, decreases BD
    • compaction/depth decreases porosity, increases BD
  19. BD vs. PD
    • % porosity=[1-(BD/PD)]x100
    • BD high------porosity low
    • BD low------porosity high
Card Set
soils test 1