Organic Matter Flashcards
1
Q
3 Reasons OM is helpful?
A
Increases structure Improves water infiltration Resists compaction More resistant to erosion Reduces bulk density
2
Q
The LIVING
A
plant roots, moles/voles (animals), bugs, bacteria
10-20%
3
Q
The DEAD
A
Recently added plant residues, manures, compost
Dead microbes and insect bodies
Sloughed off root cells/root secretions
Microbial secretions
10-20%
4
Q
The VERY DEAD
A
Completely decayed over time: complex organic substances (soil hummus)
Provides beneficial physical properties to soil (aggregation, drainage, water holding capacity)
Source residue no longer recognizable
60-80%
5
Q
What conditions do microbes need?
A
organic matter
there is greater activity in undisturbed soils
Cover crops- microbes eat 60% OM
When they eat OM they give off CO2
