1. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Chapter 2 Formation of Soils from Parent Materials Sampling moon “soil.” (NASA, Apollo 14)

2. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Figure 2.1 (a)(b)

3. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Figure 2.2

4. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Figure 2.3

5. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458

6. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458

7. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Physical Weathering Processes Unloading Temperature –Thermal Expansion –Freeze-Thaw –Frost Wedging Abrasion –Water, Ice, Wind Biological Activity –Burrows –Root Wedging

8. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Biogeochemical Weathering Processes Hydration –Intact water molecules combine with a mineral 5Fe 2 O 3 + 9H 2 O Fe 10 O 15 (9H 2 O) Hydrolysis –Water Molecule splits into hydrogen and a hydroxyl and the hydrogen replaces a cation from the mineral structure KAlSi 3 O 8 + H 2 O HAlSi 3 O 8 + K + + OH - Dissolution –Aided by small amounts of acid in the water –Soluble ions are retained in the underground water supply CaCO 3 + 2[H + (H 2 )O] Ca 2+ + CO 2 + 3H 2 O OR CaSO 4 (2H 2 O) + 2H 2 O Ca 2+ + SO 4 2- + 4H 2 O

9. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Biogeochemical Weathering Processes Carbonation –Weathering is accelerated by the presence of weak acids CO 2 + H 2 O H 2 CO 3 (Carbonic Acid) Then H 2 CO 3 + CaCO 3 Ca 2+ + 2HCO 3 - Oxidation-Reduction –Any chemical reaction in which a compound or radical loses electrons –Important in decomposing ferromagnesian minerals 4Fe + 3O 2 2Fe 2 O 3 Or 4Fe (2-) O + O 2 + 2H 2 O 4Fe (3-) OOH (Goethite)

10. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Figure 2.5 (a)(b)

11. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Figure 2.6 (a)(b)

12. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Development of Clays The breakdown of parent rock results in the development of clays

13. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Factors Influencing Soil Formation CLORPT Climate –Primarily precipitation and temperature Organisms –Especially vegetation, microbes, and soil animals Relief –Slope, aspect, and landscape position Parent Material –Geological or organic precursors to the soil Time

14. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Effects of Parent Material The parent material is what the soil and the nutrients ultimately come from –Examples Colluvium Alluvium Floodplain Glacial Marine Sediments Loess Organic Bogs

15. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Figure 2.11

16. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Figure 2.12 A productive soil in the Appalachian Mountains formed on colluvium

17. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Figure 2.14 Alluvial fans merging into a Bajada in Alaska, which will form well-drained soils

18. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Figure 2.13

19. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Figure 2.15

20. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Glacial Erosion

21. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Glacial Erosion

22. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Figure 2.17

23. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Figure 2.16 1. Till deposits of various kinds 2. Glacial-lacustrine deposits 3. The Loessial blanket 4. Area that escaped glaciation but has loess

24. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Figure 2.18

25. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Figure 2.19 Glacial Till Glacial Outwash

26. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Figure 2.20 Distribution of Dune Sands and Loess Deposits

27. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Homes carved from Loess deposits in China

28. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Figure 2.22 Development of a peat bog resulting in Histosols

29. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Effects of Climate Effective Precipitation –Depends on timing, topography, and soil type Temperature –Effects the rate of weathering Climate also affects vegetation

30. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Box 2.1 a. Seasonal Distribution, b. Temperature and Evaporation, c. Topography, d Permeability

31. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Figure 2.23 Temperature and Precipitation work together to affect depth of regolith weathered from bedrock

32. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Figure 2.24 Climate and Vegetation are interconnected

33. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Effects of Organisms Flora –Lichen, Moss, Trees Fauna –Mites, Nematodes, Springtales, Earthworms

34. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Figure 2.8 The effect of lichen etching bedrock

35. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Figure 2.25 Difference in the soil profile under grassland versus forest vegetation

36. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Change in soil Ph because of forest type

37. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Semiarid rangeland vegetation will locally enhance fertility, photos from Patagonia Argentina

38. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Figure 2.28 Prairie dog burrows help to mix the soil (called crotovinas), photo taken in Illinois

39. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Effects of Topography Slope and Aspect –Determines amount of solar radiation absorbed Parent Material Interactions –Affects the distribution of colluvium and alluvium Salt Buildup –Arid areas slats are leached from relatively higher areas to lower areas Interaction With Vegetation –Moisture regime is affected by microtopographic changes which in turn controls vegetation distributions

40. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Figure 2.29 (a)(b) Topographic influence on soil depth

41. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Figure 2.30

42. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Effects of Time All soil forming processes occur over a very long period of time The time it takes to develop a soil is relative, dependent upon –Climate –Vegetation –Human Interaction

43. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Figure 2.31

44. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 When Everything Else Is Held Equal (Sequences) Catenas –When soils are developed on the same parent material and the soils only differ on the basis of drainage due to variations in relief Chronosequence –A sequence of related soils that differ in certain properties primarily as a result of time as a soil-forming process Lithosequence –A group of related soils that differ as a result of parent material Climosequence –A sequence of soils that differ as a result of changes in climatic regimes (temperature and precipitation) Biosequence –A group of related soils that differ primarily due to variation in kinds and numbers of plants and soil organisms

45. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Four Basic Processes of Soil Formation Transformation –When soil constituents are chemically or physically modified or destroyed and others are synthesized from precursor materials Translocation –The movement of organic and inorganic materials horizontally or vertically across a pedon Additions –Inputs of materials from outside sources (i.e. plant litter) Losses –Materials that are removed from the soil profile by leaching or erosion

46. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458 Figure 2.32

47. THE NATURE AND PROPERTIES OF SOILS, 13/e Nyle C. Brady and Ray R. Weil ©2002 Pearson Education, Inc. Upper Saddle River, New Jersey 07458