Question

Why is humus considered to be the major factor in deciding yhe soil structure?

Answer 1

Humus is the bits of decayed organisms present in the soil. It usually gives the soil a blackish colour. 

Function. Humus is the major factor in deciding the soil structure because:

(i) it causes the soil to become more porous.

(ii) allows water and air to penetrate deep into the soil making available for the roots of the plants.