Components- Minerals, Organic matter ,Water ,Air

• Hans Jenny’s factors 1941 – Climate CL , Biological agents O, Relief/ topography R, Parent Material P, time T Cl O R P T

  Topography - affects drainage

• Loess – a wind blow silt parent material of dust

  soil profiles/ horizons

• O - organic material

• A- some organic material, mostly mineral, ideal for plant growth, hydrolysis happens in this layer

• E - washed out layer, mineral material, Hydrolysis happens here

• B - accumulations, clay particles and oxides ( all the stuff from hydrolysis ends up here)

• C- parent material, weathered bed rock

• R - bedrock

• A build up of calcium carbonate is sometimes called K horizon.

  How to describe soil

  1. Horizon designation

  2. Horizon boundary depths

  3. Color

  4. Texture

  5. Structure

  6. Clay films and oxidation/ reduction features

  7. Calcium carbonate accumulations

  8. Rock fragments

     Pedon – a column of soil taken from specific location, extending from the ground surface all the way down into C

     Solum- where soil development is most active AEB (not C)

     12 orders of Soil - Alfisols, Andisols, Aridisols, Entisols, Gelisols, Histosols, Inceptisols, Mollisols, Oxisols, Spodosols, Ultisols, Vertisols

     Alfisols -  moderately leached soils that have relatively high native fertility, high base status forest soils with argillic horizons

     Andisols- soils that have formed in volcanic ash or other volcanic ejecta

     Aridisols -  CaCO3-containing soils of arid regions that exhibit subsurface horizon development, soils of dry regions

     Entisols- recently formed soils, soils of recent origin

     Gelisols- soils of very cold climates that contain permafrost within two meters of the surface, soils of permafrost, cryoturbation, and ice segregation

     Histosols,- soils that are composed mainly of organic materials

     Inceptisols -  soils that exhibit minimal horizon development,embryonic soils with few diagnostic features

     Mollisols - soils of grassland ecosystems, grassland soils of steppes and prairies

     Oxisols- sesquioxide-rich, highly weathered soils of the intertropical regions, very highly weathered soils that are found primarily in the intertropical regions of the world

     Spodosols - acid soils characterized by a subsurface accumulation of humus that is complexed with Al and Fe, soils with subsoil accumulations of humus and sesquioxides

     Ultisols - low base status forest soils, strongly leached, acid forest soils with relatively low native fertility

     Vertisols - shrinking and swelling dark clay soils, clay-rich soils that shrink and swell with changes in moisture content