Humus ____.
A) is the material always comprising the topmost soil horizon
B) is dark, organic-rich material formed by bacterial decay
C) is leaf-litter
D) must include sediments
E) none of these

Question

Quizplus · Accepted Answer

Humus is dark, organic-rich material formed by bacterial decay. It is an important component of soil and is formed from the decomposition of plant and animal materials. Humus helps to improve soil fertility and structure, and also helps to retain water and nutrients in the soil.