2. Soil texture
Defined
the proportion of particle sizes in the soil mineral component
- particle size is related to pore-size distribution
. larger pore sizes occur with larger size particles
Section VI

3. ------------------- 2 mm
Particle Size
Class Name Diameter(m)
Limit of particle
diameter mm mm mm
Section VI

4. Soil Particle Relative Size Diameter Shape
(mm)
Shape
grain elevator
complex
(100’)
sand
0.05 – 2.0
angular
silt
0.002 – 0.05
basketball
(12”)
angular
clay
<0.002
flat
Stamp (1”)

5. 1). using the textural triangle (TT)
lab analysis determines mineral particle size analysis
TT determines textural classes of soils
. similar physical properties

6. General Textural Categories
Fine
Coarse
Medium

7. Location of General Textural Categories
mixed
Fine/
Medium/
Medium
Fine
mixed

8. a). characteristics of fine-textural class
(e.g.: clay, clay loam, silty clay loam)
- High nutrient and water
holding capacities
” water/foot soil
- Poor drainage
- Poor root penetration
- Prolonged Spring warm-
up period

9. b). characteristics of coarse-textural class
(e.g.: sand, loamy sand, sandy loam )
- Low water holding
capacity
” water/foot soil
- Excessive drainage
- Low in nutrients

10. 2). Using the “Feel Method
a). Method - soil sample is wetted and worked with fingers
Squeeze soil between your fingers and thumb
Extrude a ribbon of soil ¼” thick
Place moist soil sample in hand palm

11. b). “Feel” Method Approximations
Fine-Textured Soils: - form long, shiny, sticky, pliable ribbons - dry clods are very hard
Medium-Textured Soils:
- ribbons not strong, not gritty
- wet soils feel floury when dry
Coarse-Textured Soils:
- no ribbons, gritty feel
- some mineral particles are visible