Question

Decomposition rate is slow if detritus is rich in

• A. Lignin and Chitin
• B. Nitrogen
• C. Sugars
• D. Humus

Answer 1

The correct option is A Lignin and Chitin

Introduction to decomposition :
Decomposition is the process of breakdown of complex organic materials present in the dead decaying organic matter into simple inorganic compounds such as carbon dioxide, water and mineral nutrients. It is carried out by microscopic organisms such as bacteria, fungi, etc.

Factors affecting the rate of decomposition are: -
● Chemical composition of detritus
● Soil pH
● Temperature
● Moisture
● Soil aeration

Nitrogen :
Rich nitrogen content in the soil increases the rate of decomposition.

Humus :
Humification is the process of decomposition of detritus to form a cellulose and lignin-rich dark coloured, amorphous organic matter known as humus.
Detritus does not contain humus but humus is produced as a result of decomposition. However, humus is highly resistant to microbial action and cannot be easily broken down further.

Sugars :
Presence of water-soluble sugars increases the rate of decomposition

Lignin and chitin :
The presence of large complex polymers such as lignin and chitin in the detritus slows down the decomposition process.

Final answer :
(D) Lignin and Chitin