Comparative studies on physical and chemical changes during compostingof organic residues as influenced by two species of earthwormsand effective micro-organisms (EM)

Abstract

An experiment was undertaken at central experimental station, Wakawali, Maharashtra to evaluate the influence of two species of earthworms and effective micro-organisms (EM)” on compositing of organic residues during July 2008 to February 2009. In order to reduce the period of composting and improve upon its quality, studies were undertaken to monitor the changes in various physical and chemical parameters governing the process of decomposition of mango leaves, cashew leaves, shivan leaves and ain leaves using Eisenia foetida and Eudrilus eugineae species of earthworms along with EM solution. It was observed that at the end of composting significantly lowest bulk density 0.38 Mg m-3 was noted in Shivan leaves inoculated with E eugineae species of earthworm.Descending order of bulk density values after the composting were observed as, Mango leaves>Cashew leaves> Ain leaves>Shivan leaves. The highest maximum water holding capacity on 150th days of composting was recorded in Shivan leaves(239.70%) and lowest in Cashew leaves(185.00%). There was reduction in pH of Mango leaves compost inoculated with earthworm species E foetida.There was a considerable reduction in electrical conductivity of all the residues after their complete decomposition. Inoculation of earthworms to all these organic residues resulted into reduction in C:N ratio with the advancement in period up to 150 days. There was significant increase in cation exchange capacity.Initially maximum CEC {36.83 c mol (p+ ) kg-1 } was recorded in Shivan leaves treated with Eudrilus eugineae and lowest CEC {23.33 c mol (p+ ) kg-1 } was noted in Cashew leaves treated with E. foetida. Similarly at the end of composting, maximum CEC{90.67 c mol (p+ ) kg-1 } was recorded in Shivan leaves treated with Eudrilus eugineae and lowest CEC {64.83 c mol (p+ ) kg-1 } was noted in Cashew leaves treated with E. foetida.