They promote the growth of pathogenic organisms.
Explanation
Vermicomposting is a method of composting that utilizes earthworms (such as Eisenia fetida) to break down organic waste. Unlike traditional hot composting (thermophilic), vermicomposting is a mesophilic process, meaning it operates at moderate temperatures (typically 10°C–30°C).
Detailed Analysis:
- Pathogen Risks: Animal by-products like meat and dairy are high in proteins and fats. Their decomposition requires specific conditions to prevent putrefaction. Since vermicomposting does not generate high heat (above 60°C), it cannot effectively kill pathogens (such as Salmonella or E. coli) that may proliferate in rotting meat. Consequently, adding these materials promotes the growth of pathogenic organisms and attracts pests like rodents and flies.
- Decomposition Speed: While fats and proteins decompose slower than cellulose-rich plant matter, the primary reason for their exclusion is hygiene and safety, not merely the rate of breakdown.
- Toxicity: These substances are not immediately toxic to redworms. However, if they putrefy and create anaerobic conditions, the resulting environment can become harmful to the worms.
- pH Impact: The breakdown of proteins releases ammonia, which tends to increase alkalinity (raise pH) initially, rather than lowering it drastically.
Key Takeaway:
Vermicomposting systems do not reach temperatures high enough to pasteurize waste; therefore, meat and dairy must be excluded to prevent pathogen growth and pest infestation.