Question

Organic manure adds organic matter called ____________ to the soil, which restores the soil texture for better retention of water and aeration of soil.

• A. compost
• B. animal manure
• C. humus
• D. both $A$ and $C$

Answer 1

The correct option is C humus

Humus refers to the fraction of soil organic matter that is amorphous and without the "cellular cake structure characteristic of plants, micro-organisms or animals." Humus significantly influences the bulk density of soil and contributes to moisture and nutrient retention. Soil formation begins with the weathering of humus. Humus is the dark organic matter that forms in the soil when plant and animal matter decays. Humus contains many useful nutrients for healthy soil, nitrogen being the most important of all.