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2.1 Physical Characteristics
Discussion – What is organic matter?
Evaluate items in the following list as soil organic matter. Circle those you think
of as soil organic matter, draw a square around those that might become organic
matter, and cross out those you think are probably not.
Compost added to the soil surface
Living microbes on a soil surface particle
A cow patty on the soil surface
Agricultural lime
Mulch added to the soil surface
Grass blades in an ant mound
Dung that a dung beetle has brought
down to the A horizon
Urine from a horse
Fertilizer like ammonium nitrate
Worm castings in the soil
A rabbit carcass
Oak leaves
Humus
Decomposing root fragments in the soil
An ant
What were the criteria you used for including or excluding items in the soil organic
matter classification?
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