(Fig. 3). This was followed by a period of slow mineralization until
the termination of the experiment (Fig. 3). After 660 days, the
mineralization percent of the composted cow manure, paper pulp
and paper pup þ asphalt were 35.5 2.3, 31.3 3.6, 29.4 2.1%,
respectively. Lower final conversion values were observed for rice
hull, peat fiber and coconut coir with values of 21.1 2.6, 18.3 0.7
and 14.4 2.5%, respectively. SEM images of coconut coir revealed
some surface changes indicative of biodegradation (Fig. 2G and H).