Question

Which of the following processes leads to enrichment of soil by nutrients?

• A. Leaching
• B. Humification
• C. Fragmentation
• D. All of the above

Answer 1

The correct option is B Humification

The process of decomposition, i.e. breakdown of complex organic matter into inorganic substances takes place in five steps: Fragmentation, leaching, catabolism, humification and mineralisation.

Fragmentation is the process of breakdown of detritus by the detritivores (e.g., earthworm) into smaller particles.

Bacterial and fungal enzymes degrade detritus into simpler inorganic substances. This process is called as catabolism.

By the process of leaching, water-soluble inorganic nutrients go down into the soil horizon and get precipitated as unavailable salts.

Humification and mineralisation occur during decomposition in the soil.
Humification leads to the accumulation of a dark coloured amorphous substance called humus that is highly resistant to microbial action and undergoes decomposition at an extremely slow rate. Being colloidal in nature, it serves as a reservoir of nutrients.
Mineralisation is the process of degradation of humus by some microbes. The inorganic nutrients are released into the soil during this process.