VERMICOMPOST AS A SOIL AMENDMENT

Abstract

The utility of epigeic earthworm for successful degradation of organic wastes is well documented for different industries such as paper and pulp. Compared to thermal composting, vermicomposting with earthworm often produces a product with a lower mass, lower processing time, and humus content; phytotoxicity is less likely; more N is released; fertilizer value is usually greater; and additional product (earthworms) which can have other uses is produced. Therefore, vermicomposting seems to be more appropriate and an efficient technology to convert industrial waste to a valuable community resources at low input basis. However, the composting efficiency and biology of only a few epigeic earthworm species has been studied, for example, Eisenia foetida. Compost is an excellent product; being homogenous and retaining most of the original nutrients and reduced levels of organic contaminants with respect to the starting material. It can be applied to soil to increase soil organic matter content and content of nutrients, which can be released upon decomposition, improve soil structure, and increase cation exchange capacity. Composting has been updated to process organic wastes of different origin, such as sewage sludge, animal manure, and agro-industrial wastes. However, composting is a time-consuming process taking at least 6 months and requiring frequent mixing with possible losses of nutrients, that is, NH3. Additionally, earthworms reduce numbers of pathogens and the same effect is obtained in traditional composting by the increase in temperature. Vermicomposting has been successfully used for composting different types of wastes, such as municipal and industrial sludges. Though optimal moisture and the best proportions of organic waste are required for an efficient vermicomposting