In the latest years, with the wide use of mulching film,
the problems existed are also emerging. Most of the
films used currently are made of synthetic polymers,
such as polyethylene and polyvinyl chloride (PVC),
which can not be degraded themselves. Mass of plastic
piece residual in the soil lead to the destruction of soil
structure, and cause great difficulties to plowing and
sowing (Zhou and Zhu, 2002; Han and Chen, 2008;
Lu et al., 2007). To solve the problem generated by
plastic film, researches on biodegradable films attract
great attention.