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Soils & Soil Physical Properties

Unit 2.1 | Part 2 – 29

Supplemental Demonstrations & Examples

for the instructor

INSTRUCTOR OVERVIEW

These demonstrations and examples use

analogy and models to illustrate various

soil physical properties. Note the references

to sections of the detailed lecture for

specific topics.

SOIL EXAMPLES

Lecture Reference: Throughout

PURPOSE

To show examples of certain soil physical prop-

erties

MATERIALS: EXAMPLES OF SOIL TO SHOW

• Texture (sand, silt, clay, loam, etc.)


• Structure


• Hard pans


• Color (dark = high organic matter, bright = well
  drained, redoximorphic features = wetness)

BAKLAVA DEMONSTRATION

Lecture 2 Reference: A 1 a) iii

PURPOSE

To show layering akin to what is found in phyl-

losilicate (layer-lattice) clays

MATERIALS

• Baklava, preferably enough so that each student
  can have a piece

METHODS

Point out that many clay minerals are layered at

the microscopic level much the way that baklava

is and that cations are adsorbed to the sides

of clay particles much the same as the nuts are

stuck to the sides of the baklava.

TARGET DEMONSTRATION

Lecture 2 Reference: A 1 a) iii

PURPOSE

To show that clay is sticky (adhesion)

MATERIALS

• Moist clay, moistened enough so that it adheres
  to most surfaces


• A flipchart or blackboard with a target drawn
  on it


• Moist sandy loam (optional, for contrast)

METHODS

Form the clay into a ball, and throw it at the

target (test the surface first to make sure that the

clay will actually stick to it). Optionally, you can

repeat the process with sandy loam or similar to

show that it is not as sticky.

Instructor’s Supplemental Demonstrations & Examples