HUMUS

1. HUMUS FORMATION
I PG MICROBIOLOGY
SRCW

2. “Humus is defined as a complex and rather resistant
mixture of brown or dark brown amorphous and
colloidal substances modified from the original tissues
or synthesized by the various soil organisms”

4. DECOMPOSITION
SYNTHESIS
2 GENERAL TYPES OF
BIOCHEMICAL
REACTIONS

5. DECOMPOSITION
• PLANT RESIDUES BROKEN DOWN BY MICROBES LIGNIN
• OTHER SIMPLER ORGANIC COMPOUNDS BROKEN DOWN

6. SYNTHESIS

7. SOIL
PARENT ROCK
CLIMATE
TEMPERATURE
RAINFALL
TIME
FLORA
FAUNA
MICROBES
RELIEF
ALTITUDE
SLOPE
FACTORS RESPONSIBLE FOR FORMATION