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Soils & Soil Physical Properties

Part 2 – 32 | Unit 2.1

PEAT MOSS DEMONSTRATION

Lecture 2 Reference: A 11 d) i.

PURPOSE

To show how dry organic matter repels water

MATERIALS

• Dry peat moss (a handful)


• Water

METHODS

Hold up a handful of dry peat moss and pour

the water over it, showing how the water runs

off rather than soaking in.

SPONGE DEMONSTRATION

Lecture 2 Reference: A 12

PURPOSE

To provide a conceptual model of available

water capacity and field capacity

MATERIALS

• Sponge


• Water in a bowl or pan

METHODS

1. Soak the sponge in water until it is saturated.


2. Hold up the sponge until most of the water
   stops dripping. Explain that the sponge is
   analogous to soil. When the water has finished
   draining from the soil 24 hours after saturation,
   the soil is said to be at field capacity.


3. Squeeze the sponge to remove as much water
   as you can. Mention that this water would be
   analogous to what can be removed by plants
   and is the water available at the soil’s water
   holding capacity. After squeezing the sponge,
   there is still some moisture left in it and that is
   analogous to the water that is held so tightly
   in the soil that plants cannot remove it, which
   is the water content at the permanent wilting
   point.

Instructor’s Supplemental Demonstrations & Examples