Evaluation of Earthworm Species and Bedding Material Collected from Tea Plantations for Vermicomposting in Sri Lanka

Earthworms has the ability to convert organic waste into compost and this process is known as vermicomposting. This study was conducted to evaluate the suitability of three common earthworm species and four waste material collected from tea plantations as bedding material for earthworms in producing vermicompost. Three experiments were conducted and the experimental design was a Complete Randomized Design with three replicates. In the first experiment, four bedding materials that is leaves of Gliricidia (Gliricidia sepium) and Mana (Cymbopogon confertiflorus), tea prunings and refuse tea were composted using earthworm species Eudrilus euginea. Each waste material was mixed with cow dung and poultry manure, separately before using them as bedding material. The results showed that these material can be used for producing high quality vermicompost. In the second experiment three earthworm species Eisenia foetida, Periyonix excavator and Eudrilus euginea which were commonly recorded from Sri Lankan soils were evaluated for vermicomposting. Vermicomposting has increased the quality of organic material but the mean differences in nutrient levels in relation to earthworm species were non-significant (P=0.05). This indicates the suitability of all three species for vermicomposting. In the third experiment three soil amendments, vermicompost produced using Eudrilus euginea, garden compost and inorganic fertilizer were compared using tomato as an indicator crop. Vermicompost applied treatment showed significantly higher (P<0.05) fruit weight and number of branches when compared to other two treatments showing its usefulness as a soil amendment. This study shows that all factors are in place for producing vermicompost successfully in Sri Lanka.