Question

Biodegradable wastes like vegetable peelings from kitchen are usually processed by composting techniques. Which of the following option(s) regarding the processing of biodegradable wastes is/are correct?

• A. Vermi-composting is relatively faster than windrow composting, however vermi-composting is not frequently used on large commercial scale.
• B. The windrow height should be as short as possible as large windrow height may cause compaction due to the self-weight.
• C. The windrow height should be as large as possible as that will help to ensure appropriate temperature within the windrow.
• D. Earthworms facilitate the growth of microorganisms and break down complex organic molecules to simpler ones using enzymatic secretions.

Hint:

Windrow composting depends heavily on aeration; vermi-composting depends on moisture and temperature suitable for earthworms.

Answer 1

The Correct Option is A, D

Option (A): True
Vermi-composting is indeed faster because earthworms accelerate decomposition. However, it is not preferred for large-scale operations due to strict moisture, temperature, and handling requirements.
Option (B): True
Windrow height must be limited because too much height causes compaction from self-weight, reducing aeration and slowing aerobic decomposition.
Option (C): False
Very large windrows hinder oxygen transfer. Temperature rise is necessary but excessive pile height reduces porosity and airflow, which slows decomposition.
Option (D): True
Earthworms secrete enzymes and enhance microbial population, accelerating breakdown of organic matter. This is a key feature of vermi-composting.
Final Answer: (A), (D)