Ren R 441 podzolic soils

  1. diagnostic horizon
    • podzolic Bh, Bhf, Bf
    • all three are illuvial horizons, accumulation of amorphous products
  2. morphological characteristics
    • accumulation of amorphous material in B
    • texture coarser than clay
    • No Bt or Bf velow 50cm in the profile
    • >/= 10cm and has moist, crushed color of BLACK or 7.5YR or redder
  3. Bh horizon
    • h for humus
    • accumulation of colloidal humus
    • must have at least 1% OC
    • < 0.3% amorphous iron
    • colour nearly black
  4. Bf horizon
    • accumulation of colloidal iron oxide
    • at least 0.3% pyrosphosphate extractable Fe
    • 0.5-5% OC
    • high chroma, reddish colour
    • single grain structure
  5. Bhf horizon
    • assoc with soils on the west coast
    • > 5% OC
    • has 0.3+% pyrophosphate extractable Fe
    • usually single grain
  6. podzol structure
    none, single grained
  7. horizon boundaries?
    wavy, disturbed boundaries
  8. climate
    cool to cold perhumid climate
  9. PGM?
    • usually lacks carbonates
    • is acid with coarse texture (low %BS)
  10. type of vegetation
    • conifers, mixed forests, heath
    • plant groups that prefer acidic environments
  11. distribution in canada
    • boreal forest of the candian shield, appalachians, cordilleran
    • eastern hardwoods of the appalachians
    • coastal forest region of BC
    • BC interior
  12. soil forming factors: climate
    • cool temperate regions
    • net percolation (humid to perhumid)
  13. soil forming factors: organisms
    • forest (coniferous)
    • herbaceous species decomposing (fungal) to acidic leachates
  14. soil forming factors: relief
    favors downward leaching and net percolation
  15. soil forming factors: pgm
    • sandy, carbonate free, low pH
    • low buffering capacity
    • iron containing primary materials
  16. soil forming factors: time
    >3000 yrs
  17. ________ of primary materials and translocation of ________ by formation of ____________
    • chemical weathering
    • Fe and Al
    • organo-metallic complexes
  18. biogeochemical weathering processes in L horizon
    acidic litter
  19. biogeochemical weathering processes in FH horizon
    fungal decomposition
  20. biogeochemical weathering processes in Ae horizon
    intense biogeochemical activity
  21. biogeochemical weathering processes in B horizon
    • largely physical processes
    • illuviation of products translocated from above
  22. humic podzols
    • Bh horizon of 10+cm
    • occur on wettest sites
    • peaty decompressions
    • some degree of gleying (ex. Bhfgj)
  23. ferro-humic podzol
    • have Bhf of 10+cm
    • LFH or O layers
    • usually Ae
    • colour changes with depth
  24. humo-ferric podzol
    • most common of the podzols
    • has Bf horizon
    • usually LFH and Ae
    • strong red, fading gradually with depth
    • strongly acid and low BS
  25. how many orthic subgroups?
    • one for each of the 3 GGs
    • orthic humic podzol
    • orthic humo-ferric podzol
    • orthic ferro-humic podzol
  26. subgroups besides orthic
    • gleyed SG
    • orstein SG 
    • placic SG
    • duric SG 
    • fragic SG
    • sombric SG
  27. gleyed SG
    gj in upper 100cm
  28. orstein SG
    • has an orstein layer 3cm thick
    • Bfc
    • assoc with perched water table?
  29. placic subgroup
    • Bhfc or Bfc < 5mm
    • wet maritime climates
    • thin single or multiple involute bands
    • hard, vitreous, dark reddish brown
    • Fe and Mn cement
  30. duric SG
    • in all 3 GGs
    • during layer in lower B horizon
    • strongly cemented with ubrupt upper boundary
    • colour of pgm, massive structure
  31. fragic SG
    • in all 3 GGs
    • Bx or BCx in lower solum
    • high bulk density
    • firm and brittle when moist
    • had to extremely hard when dry
    • clay cemented sand?
  32. sombric SG
    • mainly in humo-ferric GG
    • has a mull Ah (earthworm activity)
    • usually lacks Ae
    • Bf horizon - in situ weathering and accumulation of iron oxide
  33. nutrient removal through ________ have potential to affect the long term productivity of podzols
    • forest harvesting
    • more susceptible to nutrient leaching
    • when whole tree is removed vs. stem harvest and leaving CWD
  34. how are toxicity issues caused in podzols?
    • acidification exacerbated by anthropogenic activities
    • can mobilize Al in soil
    • help fix by liming? to help pH increase
Author
hcunning
ID
324692
Card Set
Ren R 441 podzolic soils
Description
podzolic soils lecture
Updated