Abstract:
Small-scale composting is an effective practice within the circular economy, with
vermicomposting standing out as a method that produces high levels of Nitrogen (N),
Potassium (K), and Phosphorus (P) by accelerating the breakdown of organic waste
through the natural processes of earthworms. Vermicomposting not only enhances soil
fertility but also offers a sustainable solution for managing household and garden waste.
There are four key earthworm species used in this process: Eisenia fetida, Eudrilus
eugeniae, Perionyx excavatus, and Aporyectodea caliginosa. While previous research has
focused on specific worrn types and waste feeds, a comprehensive comparative study of
these variables has yet to be thoroughly investigated. This study aims to identi$ the
optimal combinations of worrn species and waste feed types for maximizing the
production of N, P, and K in vermicomposting. A detailed literature review was
conducted, selecting data from 135 published research papers. A meta-analysis was
performed to assess the degradation rate, moisture content (50-80%), and pH levels (6.G-
7.0), C: N ratios as they relate to vermicomposting performance. Descriptive statistics
and skewness values were analyzed to understand the impact of worm and waste types on
composting outcomes. The analysis revealed that worm type and waste type significantly
influence the degradation rate and the produciron of N, P, and K. A positive correlation
was found between wonn type (0.62) and waste type (0.45) with the degradation rate,
while the degradation rate negatively correlated with the levels of N, P, and K. In overall
view food and animal waste is more efficient in producing N and P where, animal waste
is only significant in producing K. Eisenia fettda demonstrated strong performance in
producing N (tt .60/o) and K (>1 .4o/o) across all waste types, though it was less effective
for P production. However, mixing waste feeds improved overall performance. The
highest N production (2.70%) was achieved with food waste and. Eudrilus eugeniae, the
highest P production(2.05%) with food waste and Perionyx excavatus, and the highest K
production (1.7%) with animal waste and Aporrectodea caliginosa. The study concludes
that animal waste is generally more suitable for vermicomposting, with specific worrnwaste
combinations yielding the highest nutrient levels in the compost produced.
