the effect of pesticides on the degradation of oxobiodegradable agricultural mulch films
abstract
oxobiodegradable agriculture mulch films made from polyethylene (pe) are known to
have many benefits for agriculture practice, including increased yields and resource efficiency,
without the drawback of removing the film after the growing season. however, anecdotal
evidence suggested when pesticides are applied to these films, their rate of degradation may be
affected. the goal of this investigation was to characterize the delay in degradation that occurs
when pesticides are applied to oxobiodegradable agriculture mulch films. two pesticides,
pyrinex 480 and round up, were tested in the field and laboratory environment to determine the
effects on degradation with normal and accelerated exposure conditions for the films. exposure
tests indicated the pesticides were having stabilizing effects on the pe films, delaying degradation. therefore, tests were designed to explore the chemical mechanisms underlying each
pesticide’s stabilizing influence. these included experimental and computational measurements
of redox potential to define chain breaking donor and chain breaking acceptor capacities of the
pesticides. uv (ultraviolet) screener capacity of the pesticides was also investigated. we
concluded that pyrinex 480 likely has the ability to absorb uv energy that would normally break
bonds in pe, along with some other capacity to stabilize degradation, such as the ability to accept electrons. in contrast, round up likely donates electrons or atoms to prevent degradation reactions and stabilize
pe films.