The correct option is (c).
Explanation
Vermicomposting is a method of making compost using redworms (such as Eisenia fetida) to break down organic waste. While redworms thrive on most biodegradable kitchen waste, specific environmental conditions regarding pH, salinity, and microbial balance must be maintained for their survival.
Statement-wise Analysis:
- 1. Vegetable peels: Incorrect. Vegetable peels are biodegradable organic matter. They are soft, easily digestible, and serve as an excellent food source for redworms.
- 2. Coffee and tea remains: Incorrect. Used tea leaves and coffee grounds are organic residues that decompose effectively and are safe for inclusion in a vermicomposting pit.
- 3. Pickles and vinegar: Correct. These items should not be added. Pickles contain high salt concentrations, and vinegar is highly acidic. Redworms are extremely sensitive to high salinity and acidic pH, which can cause mortality or inhibit their activity.
- 4. Milk preparations: Correct. These items should not be added. Dairy products (milk, curd, ghee) tend to ferment rapidly, creating foul odours. More importantly, they attract disease-causing microorganisms, ants, and other pests that can harm the worms and disrupt the composting process.
Key Takeaway:
In vermicomposting, materials containing excess salt, oil, vinegar, meat, and dairy products must be avoided as they alter the pit's pH and encourage the growth of pathogenic microbes harmful to redworms.