Moderate moisture and shade.
Explanation
Vermicomposting utilizes specific species of earthworms, commonly redworms (such as Eisenia fetida), to decompose organic waste. These organisms interact closely with abiotic factors in their environment. Their physiological survival depends strictly on specific ranges of temperature, moisture, and light exposure.
Option Analysis
- High temperature and direct sunlight. is incorrect: Redworms are photophobic, meaning they move away from light. Direct sunlight can rapidly dry out their skin, leading to death, as they breathe through their moist skin. Additionally, high temperatures (typically above 30°C) are detrimental to their survival.
- Freezing temperatures. is incorrect: Extreme cold or freezing temperatures significantly slow down the metabolic activity of redworms and can be fatal. They thrive best in moderate temperature ranges (approximately 15°C to 25°C).
- Moderate moisture and shade. is correct: Redworms require a moist environment to facilitate cutaneous respiration (breathing through skin). Shade is essential to prevent desiccation (drying out) and overheating. Therefore, maintaining moderate moisture and keeping the pit in a shaded area creates the optimal microclimate for their survival.
- Dry and compacted soil. is incorrect: Dry soil prevents respiration, leading to suffocation. Compacted soil restricts aeration and movement, creating anaerobic conditions that are harmful to the worms and the composting process.
Key Takeaway: Redworms used in vermicomposting require a moist, cool, and shaded environment with adequate aeration; they are highly sensitive to and cannot survive in direct sunlight, extreme temperatures, or dry conditions.