A second soil experiment was conducted to evaluate the relative
biodegradability of thirteen different test specimens in 1 1 cm
square film form. These included bio-based plastics, plastics
amended with additives that are meant to enhance biodegradability
and natural fiber composites. The experiment was conducted
for a period of 660 days. The initial moisture content of the
mixeswas 16.6 2.1% and the final mean soil moisture content on a
wet-weight basis across all treatments was 14.3 3.3% (wetweight
basis) which is 84.9 2.4% of the 60% moisture holding
capacity of the soil mixture. The positive control (cellulose paper)
exhibited 74.2 4.5% conversion during the period of incubation.