1. Soils, Soil Processes & Decomposition

8. Surface area increases as particle size decreases. Surface area influences ability to hold water and nutrients.

9. Soil formation processes – Laterization Silicate rich parent material Free polyphenols disperse clays & assist movement f/A->B Older, more intense weathering Rapid decomposition of organics Clays weather to Al and Fe oxides - SiO4 gone Red or Yellow color Infertile, rapid and almost direct recycling; little nutrient storage

11. Entisols Udipsamment

12. Entisols EudifluventLithic Ustorthent

13. Inceptisols Typic HydrandeptUmbric Vitandrept

14. Alfisols Typic Hapudalf

15. Ultisols Typic Hapudult

16. Oxisols Tropeptic Eutrorthox

17. Soil formation processes – Podsolization Substrate usually well-drained quartz sand, acid, igneous Transport of Fe and Al by soluble organic compounds. Plants from low N or low P soils produce polyphenols E = intense eluviation B = illuviation of organic, Al, & Fe Distribution world-wide, greatest in boreal zone Also in temperate and tropical zones on acid quartz sands End point = acid, low nutrients Bleached E and Dark B with Organics, Fe and Al in B

20. Spodisols Aeric HaplaquodTypic Haplorthod

21. Soil formation processes – Calcification Drier sites; Calcium not leached out of soil profile Gradient of decreasing precipitation matches thinner A horizon A horizon high in organic content, mostly roots of grass Often highly fertile Climate/disturbance appears unsuitable for trees

23. Molliosols Typic HaplaquolTypic Argiudoll

24. Typic Argiustol Typic Haplustol

25. Aridisols Typic Haplargid Petrocalcic Paleargid

26. Typic Salorthid

28. Histisols Limnic Medisaprist

29. Vertisols