Q. Consider the following statements:
  1. Humus undergoes decomposition at an extremely slow rate.
  2. Humus is colloidal in nature and serves as a reservoir of nutrients.
Which of the above is / are correct?

Answer: Both 1 and 2
Notes: Humification and mineralisation occur during decomposition in the soil. Humification leads to 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. The humus is further degraded by some microbes and release of inorganic nutrients occur by the process known as mineralization.

This question is part of UPSC Daily 20 MCQ Series Course on GKToday Android app.