SOIL SEPARATES. Soil Evaluator Day 2, Presentation 3-3/27/2018. Soil Texture, Page 1 TITLE 5 SOIL EVALUATOR CERTIFICATION TRAINING SOIL TEXTURE

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Rosamund Davidson
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Massachusetts Amherst Presented by: New England Interstate Water Pollution Control Commission SOIL SEPARATES Soil is made up of individual particles, which are classified by the size of the particle.

1 Soil Evaluator Day 2, Presentation 3-3/27/18 TITLE 5 SOIL EVALUATOR CERTIFICATION TRAINING SOIL TEXTURE Prepared for: Commonwealth of Massachusetts Department of Environmental Protection By L.A. Spokas, PhD, Stockbridge School of Agriculture University of Massachusetts Amherst Presented by: New England Interstate Water Pollution Control Commission SOIL SEPARATES Soil is made up of individual particles, which are classified by the size of the particle. There are many classification schemes as seen in the next slide, but soil scientists use the USDA scale. Soil separates are < 2 mm in size, and do not include the portion of the soil that is organic. USDA Unified AASHO Sieve opening in inches / / 4 ½ Coarse Gravel Sand Silt Clay Gravel Fine Gravel U.S. standard sieve numbers Coarse Very Coarse Medium Coarse Medium Fine Very Fine Sand Fine Sand Silt-Clay Coarse Medium Fine Coarse Fine Silt Clay Silt or Grain size in millimeters Soil Texture, Page 1

Soil Evaluator Day 2, Presentation 3-3/27/18 USDA TEXTURAL CLASSES > 2 mm Gravel or larger (not soil) > 1 mm < 2. mm Very Coarse Sand (vcs) >.5 mm < 1. mm Coarse Sand (cs) >.25 mm <.

2 Soil Evaluator Day 2, Presentation 3-3/27/18 USDA TEXTURAL CLASSES > 2 mm Gravel or larger (not soil) > 1 mm < 2. mm Very Coarse Sand (vcs) >.5 mm < 1. mm Coarse Sand (cs) >.25 mm <. mm Sand (Medium) (s) >.1 mm <.25 mm Fine Sand (fs) >.5 mm <.1 mm Very Fine Sand (vfs) >.2 mm <.5 mm Silt (sil) <.2 mm Clay (c) Very Coarse Sand Coarse Sand Sand 1 mm Fine Sand Very Fine Sand Silt Clay Soil Texture, Page 2

3 Soil Evaluator Day 2, Presentation 3-3/27/18 Fine Sand Medium Sand Coarse Sand Soil Texture, Page 3

4 Soil Evaluator Day 2, Presentation 3-3/27/18 Very Coarse Sand Gravel 2 75mm (.8 3 ) in size Sand ½ to 2mm in size Boulders Erratic Cobbles Soil Texture, Page 4

percent silt silt 1 percent Class I Class

5 Soil Evaluator Day 2, Presentation 3-3/27/18 NRCS Soil Textural Triangle 3 y y 1 y percent y silty silty silt percent silt silt 1 percent Title 5 Textural Classes for Design Purposes 1 percent 3 y y y y 1 3 silty silty silt 3 percent silt silt 1 percent Class I Class II Class III Class IV MEASURING/ESTIMATING SOIL TEXTURE Soil Texture, Page 5

6 Soil Evaluator Day 2, Presentation 3-3/27/18 Soil Texture, Page 6

7 Soil Evaluator Day 2, Presentation 3-3/27/18 Soil Texture, Page 7

8 Soil Evaluator Day 2, Presentation 3-3/27/18 HAND TEXTURING SOILS Moist Sample Does Not Ribbon or Ribbons Weakly A1. Moist * will not form a cast; or * forms a weak cast which crumbles when touched SAND A2. Moist * soil will form a weak cast that crumbles when transferred from one hand to another * will stain fingers slightly LOAMY SAND Soil Texture, Page 8

Moist * forms stable cast that withstands

a weak ribbon <1 and may feel slightly sticky *

9 Soil Evaluator Day 2, Presentation 3-3/27/18 Moist Sample Does Not Ribbon or Ribbons Weakly A3. Moist * forms stable cast that withstands moderate handling * strongly stains fingers * feels gritty SANDY LOAM A4. Moist * forms stable cast that withstands moderate to strong handling * s with >% may form a weak ribbon <1 and may feel slightly sticky * does not feel gritty LOAM Soil Texture, Page 9

Soil Evaluator Day 2, Presentation 3-3/27/18 Moist Sample forms Ribbon > 1"

5 ) * feels smooth, sometimes somewhat greasy, when rubbed between fingers

5" that feel sticky * soil is plastic and sticky * forms wire 2" long that

Moist * soil feels somewhat gritty when rubbed between fingers * forms

Moist * cast is very durable * forms wire 3" long * forms long flexible

10 Soil Evaluator Day 2, Presentation 3-3/27/18 Moist Sample forms Ribbon > 1" B1. Moist * forms stable cast * forms a moderate ribbon (>1 but 1.5 ) * feels smooth, sometimes somewhat greasy, when rubbed between fingers SILT LOAM B2. Moist * very stable cast * forms ribbons 1.5" that feel sticky * soil is plastic and sticky * forms wire 2" long that is < 1/8 " in diameter SILTY CLAY LOAM Moist Sample forms Ribbon > 1" B3. Moist * soil feels somewhat gritty when rubbed between fingers * forms ribbons 1.5" that feel sticky * soil is plastic and sticky * forms wire 2" long that is < 1/8 " in diameter B4. Moist * cast is very durable * forms wire 3" long * forms long flexible ribbon * soil is very plastic and very sticky CLAY LOAM CLAY Soil Texture, Page 1

Soil Evaluator Day 2, Presentation 3-3/27/18 NRCS Soil Textural Triangle 3 y y 1 y percent y 1 3 3 silty Soil Sample: 45% 37% silt 18% silty silt percent silt

11 Soil Evaluator Day 2, Presentation 3-3/27/18 NRCS Soil Textural Triangle 3 y y 1 y percent y silty Soil Sample: 45% 37% silt 18% silty silt percent silt silt 1 percent NRCS Soil Textural Triangle 3 y y 1 y percent y silty Soil Sample: 48% 44% silt 8% silty silt percent silt silt 1 percent Soil Texture, Page 11

12 Soil Evaluator Day 2, Presentation 3-3/27/18 NRCS Soil Textural Triangle 3 y y 1 y percent y silty Soil Sample: 76% % silt 4% silty silt percent silt silt 1 percent Soil Texture, Page 12

Lesson 1: Identifying Texture in Soil

Lesson 1: Identifying Texture in Soil 1 Clods Loam Peds Permeability Soil structure Soil texture Soil workability Textural triangle Water-holding capacity 2 I. A. Soil texture is the fineness or coarseness