Abstract:
Chemical composition of compost is an important indicator that determines the quality of
compost. This study compared the chemical composition of vermicompost resulting from
the process of vermicomposting alone with combined vermicomposting and composting
with addition of egg shells flour and fish meal. Organic wastes used were the mixture of
spent mushrooms waste, coconut husks, cow dung, vegetables residue, and leaf litter.
Lumbricus rubellus was the species of earthworm used in the vermicomposting process. In
the composting process, egg shells flour and fish meal are added into the vermicompost as
additives materials. The results indicate that the combined vermicomposting and
composting process with addition the additives materials improves the chemical
composition of vermicompost compared to using vermicomposting process alone. The
change of chemical composition was indicated by a decrease in C-organic content and C/N
ratio by 29% and 99%, respectively, while the content of N, P, K and S increased by 52%,
67.5%, 29% and 25%, respectively due to the addition of additives material in the
composting process. The largest increase of vermicompost nutrient content occurred in the
Ca content by an average of up to 7-fold. While polyphenols, lignin and cellulose content
of vermicompost decreased slightly. The treatment of two mixture (a) spent mushrooms
waste, cow dung and vegetables residue, and (b) spent mushroom waste, cow dung,
vegetables residue, and leaf litter gave the best chemical composition. However, to
determine the quality, we need to test the product in a plant growth bioassay as a follow-up
study.
