Zonal Classification of Soil by USDA - 12 Soils Categorized YouTube Lecture Handouts

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Zonal Classification of Soil by USDA - 12 Soils Categorized

Zonal Classification of Soil

Illustration: Zonal Classification of Soil
Table of Soil OrderTable of Soil Order
Soil orderDefining characteristicsPercent earth land area
AlfisolModerate leaching; B horizon enriched in clay; humid forest vegetation9.77
AndisolVolcanic-ash parent material0.73
AridisolHot, dry climate; weak B horizon18.53
EntisolLittle or no horizonation or swelling clay10.61
GelisolPermafrost within 2 m of land surface-
HistosolOrganic parent material1.84
Illustration: Zonal Classification of Soil
Illustration: Zonal Classification of Soil
Illustration: Zonal Classification of Soil
Illustration: Zonal Classification of Soil
Illustration: Zonal Classification of Soil
Illustration: Zonal Classification of Soil
Table of Soil Zonal ClassificationTable of Soil Zonal Classification
InceptisolLittle or no B horizon development21.80
MollisolThick, soft, black A horizon5.99
OxisolHot, humid climate; A horizon enriched in iron & aluminum oxides & kaolinite7.00
SpodosolCool, humid climate; B horizon enriched in iron & aluminum oxides & organic matter; sandy parent material3.45
UltisolWarm, humid climate; B horizon enriched in clay; extensive leaching8.12
VertisolLittle or no horizonation; high content of swelling clay2.23
Illustration: Zonal Classification of Soil
Illustration: Zonal Classification of Soil
Illustration: Zonal Classification of Soil
Illustration: Zonal Classification of Soil
Illustration: Zonal Classification of Soil
Illustration: Zonal Classification of Soil

Soil Orders Associated with Climates

  • Oxisols - Af [Aw]
  • Ultisols - Cfa [Af, Aw]
  • Alfisols - Aw, Cs, Cfa, Dfa, Dfb
  • Spodosols - Dfb, Dfc
  • Gelisols - ET [Dfc, Dw]
  • Mollisols – dry sections of Cfa, Dfa, Dfb and wet margins of BSk
  • Aridisols - BWh, BWk

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