Tests of Starch-based Biodegradable Plastic Film's Degradation Effects

The degradation effects of three kinds of starch-based degradable mulching films in soil were compared with ordinary mulching film as control using lab simulation. The effects of different films on soil catalase, invertase activities and microorganisms were also studied. The results showed that starch-based degradable film C, the most degradable one, was degradable completely in there months in humus soil and six months in pure sandy soil, and degradable film A, B was degradable completely in six months in humus soil. The soil enzyme activities of all treatments in the hums soil were higher than those in the pure sandy soil, while in the same soil the treatment C had the highest soil enzyme activities, A,B secondly, but they have no significant difference. The regularities of bacteria and actinomycetes were consistent with that of soil enzyme activities. No significant difference of fungi number was observed between two kinds of soil while C treatment had larger fungi number than other treatments in the same soil.