4-Soil_Physical_Properties.pdf

Transcript

1. EES 140: Spring 2017 Kaizad F. Patel 1 EES 140 Soil Science Spring 2017 Kaizad F. Patel Soil profile image credits: University of Idaho, Michigan State University, NRCS 1. Color 2. Texture 3. Density 4. Consistence 5. Atterberg Limits 6. Drainage 2 Outline
2. EES 140: Spring 2017 Kaizad F. Patel 2 3 Organic matter mollic epipedon folistic epipedon histic epipedon 4
3. EES 140: Spring 2017 Kaizad F. Patel 3 5 Black doesn’t always mean organic manganese dioxide 6 Drainage and redox Redox Mottling Gleying Images: www.nesoil.com, www.nzsoils.org.nz Redox conditions? Drainage?
4. EES 140: Spring 2017 Kaizad F. Patel 4 7 Redox 8 Drainage taxonomy
5. EES 140: Spring 2017 Kaizad F. Patel 5 9 Topography and soil color DRAINAGE WAY TOE-SLOPE FOOT-SLOPE SHOULDER SUMMIT Source: Soil Science Society of America 10 Eluviation
6. EES 140: Spring 2017 Kaizad F. Patel 6 11 Precipitation of salts calcium 12 Effect of moisture dry moist
7. EES 140: Spring 2017 Kaizad F. Patel 7 13 Hue Value/Chroma dominant spectral color degree of darkness or lightness of the color strength/saturation of spectral color 14 Soil hues 10R 2.5YR 5YR 7.5YR 10YR 2.5Y 5Y red yellow
8. EES 140: Spring 2017 Kaizad F. Patel 8 15 16 The Munsell System Image: Cecil Series University of Idaho - CALS 5YR 5/4
9. EES 140: Spring 2017 Kaizad F. Patel 9 Images: University of Idaho - CALS 17 Soil Taxonomy Mollic epipedon Dominant color with chroma of 3 or less, moist Albic materials Color value of 3, moist Chroma of less than 2 Spodic materials Hue of 5YR or redder Color of 10YR 3/1 18 Bangor soil series A horizon has hue of 10YR to 5Y, value of 3 or 4, and chroma of 1 to 3. E horizon has hue of 10YR to 5Y, value of 5 or 6, and chroma of 0 to 2 Bs horizon has hue of 5YR to 10YR, value of 3 to 5, and chroma of 3 to 8. BC horizon has hue of 7.5YR to 5Y, value of 4 to 6, and chroma of 2 to 8 Image taken at Dwight B. DeMerritt Forest, ME
10. EES 140: Spring 2017 Kaizad F. Patel 10 19 EGU blog Glass beads of the Viking Age Munsell blog 20 The Soil Colors of the National Parks (web link)
11. EES 140: Spring 2017 Kaizad F. Patel 11 the relative proportions of sand, silt, clay in a soil 21 mineral particles, <2.0 mm in equivalent diameter, ranging between specified size limits 22 Soil Separates
12. EES 140: Spring 2017 Kaizad F. Patel 12 mineral particles, <2.0 mm in equivalent diameter, ranging between specified size limits 23 Soil Separates mm 2.0 - 1.0 1.0 - 0.5 0.5 - 0.25 0.25 - 0.10 0.10 - 0.05 Silt 0.05 - 0.002 Clay <0.002 SAND USDA Classification of Soil Separates Fine Sand Very Fine Sand Silt Clay Very Coarse Sand Coarse Sand Medium Sand Sand – gritty, low nutrient and water retention Silt – velvety, medium to low nutrient and water retention Clay – sticky and ribbons, high nutrient and moisture retention 24
13. EES 140: Spring 2017 Kaizad F. Patel 13 mineral particles, <2.0 mm in equivalent diameter, ranging between specified size limits 25 Soil Separates does not include OM does not include coarse fraction > 2 mm = coarse fraction < 2 mm = fine fraction 26 Soil texture triangle
14. EES 140: Spring 2017 Kaizad F. Patel 14 27 50% clay 20% silt 30% sand Total = 100% 28 Loam Exhibits properties of sand and clay in equal amounts Does this mean loam contains sand and clay in equal amounts?
15. EES 140: Spring 2017 Kaizad F. Patel 15 29 What is the texture of the soil? 10% clay 60% sand Sandy loam silt? 30 Rock Fragments
16. EES 140: Spring 2017 Kaizad F. Patel 16 Soil texture influences specific surface area 31 Importance of soil texture 32 specific surface area surface area per unit mass units: m2/g Michael J. Singer and Donald N. Munns Soils: An Introduction, 6e smaller particles = greater specific surface area
17. EES 140: Spring 2017 Kaizad F. Patel 17 33 Specific surface area 1536 mm2 = 1181.5mm2/g 384 mm2 =295.4mm2/g Specific surface area and adsorption 34 adsorption vs. absorption greater surface area greater adsorptive capacity =
18. EES 140: Spring 2017 Kaizad F. Patel 18 Specific surface area and adsorption 35 H2 O water water retention? drainage? erosion? shrink-swell capacity? Specific surface area and adsorption 36 Ca+2 Na+ Mg+2 nutrients
19. EES 140: Spring 2017 Kaizad F. Patel 19 Specific surface area and adsorption 37 O2 CO2 gases porosity? Specific surface area weathering 38 charges microorganisms
20. EES 140: Spring 2017 Kaizad F. Patel 20 1. “Feel” 2. Mechanical Analysis by Hydrometer Method 3. Mechanical Analysis by Pipette Method 39 field lab 40
21. EES 140: Spring 2017 Kaizad F. Patel 21 1. “Feel” 2. Mechanical Analysis by Hydrometer Method 3. Mechanical Analysis by Pipette Method 41 Stokes’ Law 42 Stokes’ Law: settling velocity For a given solid in a given liquid V = kD2 V ∝ D2 Bigger particles settle out of suspension earlier. V = settling velocity g = gravitational acceleration ρp = density of particle ρf = density of fluid D = diameter of particle µ = viscosity of fluid Stoke’s Law V=g ρp −ρf D2 18µ
22. EES 140: Spring 2017 Kaizad F. Patel 22 43 Stokes’ Law: settling velocity D 2D V 4V V ∝ D2 Solve: Radius 5 cm, velocity = V Radius 25 cm, velocity=? Coarse soil particles settle out first Hydrometer method Pipette method 44 Stokes’ Law Stoke’s Law V ∝ D2
23. EES 140: Spring 2017 Kaizad F. Patel 23 45 46 You put 5 pedologists in a pit together, they return with 7 different opinions.
24. EES 140: Spring 2017 Kaizad F. Patel 24 47 sand silt 30 seconds 12 hours pipette hydrometer Transmission Electron Microscopy Scanning Electron Microscopy X-ray attenuation Particle counting (Coulter Counter) Light scattering 48 Modern techniques Electron Microscopy David J. Morgan, Wikimedia
25. EES 140: Spring 2017 Kaizad F. Patel 25 the arrangement of sand, silt, clay, and organic particles in soil 49 Dave Lindbo discusses soil structure (video) 50
26. EES 140: Spring 2017 Kaizad F. Patel 26 51 structural aggregate A horizon Surface horizons OM 52 Granular structure David Lindbo, Soil Science flickr
27. EES 140: Spring 2017 Kaizad F. Patel 27 B horizon 53 Blocky structure Blocky structure A. Jordán. EGU Blogs 54 Angular blocky John Kelley, Soil Science flickr Subangular blocky David Lindbo, Soil Science flickr
28. EES 140: Spring 2017 Kaizad F. Patel 28 55 Prismatic structure John Kelley, Soil Science flickr EGU Blogs 56 prism
29. EES 140: Spring 2017 Kaizad F. Patel 29 high salt concentrations arid climates 57 Columnar structure Flint Hills Guide Compacted soils 58 Platy structure Dave Lindbo, soil science flickr A. Jordán. EGU Blogs
30. EES 140: Spring 2017 Kaizad F. Patel 30 59 no aggregates single grained individual particles do not form aggregates massive the entire horizon appears cemented sandy soils Type Class Grade ped name size distinctness 60
31. EES 140: Spring 2017 Kaizad F. Patel 31 61 Grade (Strength/ firmness) Structureless Weak peds cannot be removed without being destroyed Moderate peds can be removed from the profile Strong peds, when removed, are rigid and durable in the hand Strong Prismatic John Kelley, Soil Science flickr 62
32. EES 140: Spring 2017 Kaizad F. Patel 32 water flow air circulation 63 Why is structure important? Colorado State University Biological factors Physico-chemical factors 64 Formation and stabilization of aggregates
33. EES 140: Spring 2017 Kaizad F. Patel 33 65 Organisms: Pedoturbation Plants Mammals Macroinvertebrates earthworms termites Burrowing Breaks up big clumps Pushes soil particles together 66 Organisms: roots and fungal hyphae Soil particles enmeshed in sticky networks
34. EES 140: Spring 2017 Kaizad F. Patel 34 67 Organisms: organic glues soil aggregate stability Glomalin Produced by mycorrhizae Glycoprotein Root exudates Polysaccharides – sticky bacteria Polysaccharides – sticky sugar sugar-protein fungi associated with plant roots 68 Physico-chemical: pedoturbation Freeze-thaw Drying of clay domains Pushes soil particles together Shrink-swell Cracks in clay Cracks in clay
35. EES 140: Spring 2017 Kaizad F. Patel 35 69 Physico-chemical: flocculation cation bridging between clay platelets Calcium flocculant Sodium deflocculant, dispersant 70 Physico-chemical: cementation by OM aggregates fall apart aggregates are stable
36. EES 140: Spring 2017 Kaizad F. Patel 36 71 Physico-chemical: tillage John Deere Tillage can promote or destroy aggregation. 72 Physico-chemical: tillage Tillage can promote or destroy aggregation. break large clods into aggregates incorporate OM into soil oxidative loss of OM (long term) crush and smear soil aggregates (if wet) puddled soil well-granulated soil
37. EES 140: Spring 2017 Kaizad F. Patel 37 73 mass per unit volume of a substance ρ = mass volume density 74 rho g cm3 g/cm3 density of water = 1 g/cm3 at standard temperature and pressure 1 cm3 of water weighs 1 g density of 1 g water vs. 10 g water?
38. EES 140: Spring 2017 Kaizad F. Patel 38 75 Mass of soil particles divided by volume of the solid soil particles Mass of soil particles divided by bulk volume of soil Units? 76 Mass same Bulk volume greater Which type of density is greater?
39. EES 140: Spring 2017 Kaizad F. Patel 39 77 The metric system micro milli centi kilo mega gram (g) 10-6 10-5 10-4 10-3 10-2 10-1 10 102 103 104 105 106 liter (L) meter (m) 1 Mg/m3 = 1 g/cm3 µg mg cg kg Mg 1 kilogram = 2.2 pounds
40. EES 140: Spring 2017 Kaizad F. Patel 40 79 80 Influence of Porosity less pore space more pore space bulk density? total pore space
41. EES 140: Spring 2017 Kaizad F. Patel 41 81 Influence of texture size of pores vs. total pore space sands vs. clays 82 Influence of OM Low bulk density
42. EES 140: Spring 2017 Kaizad F. Patel 42 83 Influence of Location in profile surface bulk density? subsurface 84 Influence of land management no till BD decreases (short term) BD increases tilling compaction Long-term: loss of OM till BD increases
43. EES 140: Spring 2017 Kaizad F. Patel 43 85 water infiltration and runoff composition 86 Organic Matter ~ 0.2 Mg m-3 Mineral Soils (average) ~2.65 Mg m-3 Gibbsite (Al(OH)3 ) ~2.00 Mg m-3 Hematite (Fe2 O3 ) ~5.3 Mg m-3 Galena (PbS) ~7.6 Mg m-3
44. EES 140: Spring 2017 Kaizad F. Patel 44 penetration porosity 87 OM 88
45. EES 140: Spring 2017 Kaizad F. Patel 45 total percent pore space 89 Soil A 2.5 Mg/m3 2 Mg/m3 Soil B 2.5 Mg/m3 1 Mg/m3 Which soil has higher porosity? Particle density Bulk density same mass lower bulk density = more volume more pore space Total Soil Porosity = 100−( Db Dp 100) 90 The densities of a soil are: 2 Mg/m3 1 Mg/m3 What is the porosity of the soil? 50%
46. EES 140: Spring 2017 Kaizad F. Patel 46 Total Soil Porosity = macropores + micropores 91 total pore space vs. pore size resistance to mechanical stress
47. EES 140: Spring 2017 Kaizad F. Patel 47 The ease with which soil can be reshaped or ruptured Amount of forced needed to crush a clod Manner in which soil responds to the force 93 Rupture resistance Stickiness Plasticity Penetration resistance 94
48. EES 140: Spring 2017 Kaizad F. Patel 48 Strength of soil to withstand applied stress 95 Rupture resistance  Loose  Soft  Slightly hard  Hard  Very hard  Extremely hard 96 Dry soils  Loose  Very friable  Friable  Firm  Extremely firm  Slightly rigid Wet and moist soils Rupture resistance What kind of food do pedologists like? Anything, as long as its friable soil clod crumbles increasing force
49. EES 140: Spring 2017 Kaizad F. Patel 49 97 Stickiness adhesion vs. cohesion clinging of like molecules clinging of unlike molecules 98 Stickiness
50. EES 140: Spring 2017 Kaizad F. Patel 50 99 Plasticity elastic vs. plastic object is permanently deformed does not regain original shape when force is removed object is not permanently deformed regains original shape when force is removed Degree to which “puddled” or reworked soil can be permanently deformed without rupturing 100 Plasticity
51. EES 140: Spring 2017 Kaizad F. Patel 51 Consistence Resistance to rupture Used by soil scientists Consistency Resistance to penetration Used by engineers 101 102 critical limits of water content in fine grained soil
52. EES 140: Spring 2017 Kaizad F. Patel 52 103 soil can be molded crumbly soil behaves like a viscous liquid 104 more compressibility more shrink-swell capacity high LL values
53. EES 140: Spring 2017 Kaizad F. Patel 53 105 coefficient of linear extensibility change in length of clod when it loses moisture high COLE = high shrink-swell capacity 106
54. EES 140: Spring 2017 Kaizad F. Patel 54 1. Excessively drained 2. Somewhat excessively drained 3. Well Drained 4. Moderately Well Drained 5. Somewhat Poorly Drained 6. Poorly Drained 7. Very Poorly Drained 8. Subaqueous 107 Soil Drainage Classes water table upper surface of zone of saturation groundwater water within the saturated zone vadose zone unsaturated zone above the water table capillary fringe zone of wetting by capillary movement
55. EES 140: Spring 2017 Kaizad F. Patel 55 110 Why is drainage important? Plants Water damage to roots Oxygen availability Chemistry Redox conditions Habitat for flora and fauna weathering
56. EES 140: Spring 2017 Kaizad F. Patel 56 Redoximorphic features – presence and location gleying (color) mottles Soil texture Rooting depth (unofficial) 111 How to determine drainage class 112
57. EES 140: Spring 2017 Kaizad F. Patel 57 http://nesoil.com/plymouth/catena.gif 113 114 Topography and soil color DRAINAGE WAY TOE-SLOPE FOOT-SLOPE SHOULDER SUMMIT Source: Soil Science Society of America drainage
58. EES 140: Spring 2017 Kaizad F. Patel 58 116
59. EES 140: Spring 2017 Kaizad F. Patel 59 Soil Physical Properties 117