Soil Forming Factors“Soil Orders”Transect from Arctic to GulfTransect from NE to SW U.S.Non-Regional Soil OrdersGEO 155 1st Edition Lecture 17Last Lecture SoilsOutline of Current LectureI. Soil DistributionII. Distribution of Soil Typesa. Transect from Arctic to Gulf Coast through Eastern North Americab. Transect from Northeast to Southwest United Statesc. Some “Non-Regional SoilsCurrent LectureSoil Forming FactorsClimateOrganismsReliefParent Material – where soil came fromTime – how long soil has been developing“CLORPT”“Soil Orders”Transect from Arctic to Gulf1. (tundra) Gelisol – frozen soil2. (needle leaf evergreen forest) Spodosol – distinct O Horizon, minimal A Horizon, acidic, iron oxides dissolved and removed from E Horizon making it pale, concentration of iron oxides in B Horizon (red)These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.3. (temperate broadleaf deciduous forest) Alfisol – leaves are easier to break down making the A Horizon distinct (dark), E Horizon lost clay to B Horizon (not a big color difference, texture is less stiff in E and more sticky in B)4. (southeast) Utisols – like Alfisol except the horizons are deeper, fewer nutrients, redder color (Time – in northeast, ice melted from ice age so soil is younger than the southeast soil that was not covered in glaciers, leaching, leaks more iron oxides)Transect from NE to SW U.S.5. (grasslands) Mollisol – Midwest; deep, dark A Horizon making it agriculturally productive; might find clay moving from E to B (climate is drier so no rain to move the clay)6. (subtropical desert shrubland) Aridsol – southwest; slight A Horizon; if there is an E or B horizon, it means that the climate was wetter a long time agoNon-Regional Soil Orders7. Entisols – young soils with weak A Horizons8. Vertisols – wet-dry seasons; smectites – clay that absorbs water – deep cracks in soil during dry season leads to mixing of soil from the top through the cracks, soils swells during wet season, covers top (vertical
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