GROWTH AND REPRODUCTION OF THE VERMICOMPOSTING EARTHWORM PERIONYX EXCAVATUS AS INFLUENCED BY FOOD MATERIALS

An outdoor study was undertaken using polyethylene containers to asses s the suitability of different organic residues, soybean straw (Glycin e max L. Merril,), wheat straw (Triticum aestivum L.), maize stover (Z ea mays L.), chickpea straw (cicer arietinum L.) and city garbage, as food for the tropical epigeic earthworm Perionyx excavatus, and to ass ess the influence of this earthworm on the decomposition of these mate rials. Maize stover was found to be the most suitable of the food mate rials used. Population growth of FI excavatus was enhanced by addition of these organic materials in the temperature range 24 degrees-30 deg rees C, while the population was adversely affected above 30 degrees C in a vermiculture system. Addition of earthworms accelerated the brea kdown of residues, which ultimately resulted in a lowering of the C:N ratio, water-soluble carbon and carbohydrates, and increased ash perce ntage and cation exchange capacity compared with their respective cont rols.