Which of the following is not true for humus?

Assertion: Death is important in the life cycle of an organism.
Reason: It helps in the recycling of elements in the environment.

In decomposition,humus is further degraded by some microbes and the release of inorganic nutrients occurs by the process known as...

Decomposition rate is slower if detritus is rich in........

Identify the processes $P, Q,$ and $R$ in the following descriptions:
$I -$ The process of breaking down detritus into smaller particles $- P$
$II -$ Bacterial and fungal enzymes degrade detritus into simpler inorganic substances $- Q$
$III -$ Water-soluble inorganic nutrients go down into the soil horizon and get precipitated as unavailable salts $- R$
Select the correct option for $P, Q,$ and $R$.

Which of the following statements is correct regarding Humus?
$(P)$ It is colloidal in nature.
$(Q)$ It is rich in nutrients.
$(R)$ It is highly resistant to microbial decomposition.