Abstract:
The study investigates the effect of the endogenic earthworm Pontoscolex corathrurus on soil fertility
and plant growth and three epigenic earthworms Periyonix excavatus, Eudrilus eugenia and Eisenia
foetida on vermocomposting. At the organic farm site, year round abundance of P. corathrurus ranged
from 4.95-19.6 for adults, 2-13.25 for juveniles and 2.2-7.3 for cocoons and in integrated farm site
from 2.2-15.6 for adults, 1.5-11 for juveniles and 0.8-4.6 for cocoons. Effect of P. corathurus activity on
soil fertility relieved that worm casts are significantly high in N (9.7-6.5%) and C (5.7-3.5%) content
than surrounding soil. The pH of casts was neutral compared to the fluctuating pH of surrounding soils,
in both sites Presence of P. corathurus in pot experiments, significantly increased the growth of Zea
maiz when inoculated with 7 earthworms per pot. Culturing of the 3 selected epigenic earthworms in 7
composting media, containing cow dung, vegetable refuse and rice straw in different ratios, showed that
presence of cow dung significantly increased the multiplication rate. Vermicomposting yielded com post having higher N, P, Fe, and Mn levels, better particle size in comparison to the controls. Findings
of the study confirm that earthworms commonly found in Sri Lanka can be easily used for soil fertility
improvement and vermicomposting without having to import species from elsewhere.
