Impacts of Degradable Film Mulch on GHG Emissions in Paddy Fields and Rice Yield: A Case Study

Paddy fields are a key agricultural ecosystem for achieving carbon neutrality in southern China, with significant potential to sequester carbon and mitigate emissions of CO2, CH4, and N2O. Film-covering is an emerging agricultural technique in rice production systems in China. This study evaluated the effects of degradable film coverings on greenhouse gas (GHG) emissions and rice yield. It provides an assessment of different mulching practices in paddy fields by employing controlled greenhouse experiments as well as field experiments. A key innovative aspect lies in the evaluation of not only different film types but also their varying thicknesses, a factor largely unexamined in previous studies. Greenhouse and field experiments were conducted using three thicknesses of biodegradable films (BMs; 0.01 mm, 0.015 mm, and 0.02 mm), one paper film (PM), and a non-film treatment (CK). Results showed that BM treatments reduced CO2 and CH4 emissions by more than 14.01% and 32.17%, respectively, compared with CK in the greenhouse experiment. Additionally, the film-covered treatment increased soil organic carbon content by 32.24–46.66% at rice maturity in the field experiment. These findings suggest that covering rice fields with 0.02 mm BM not only promotes ecological sustainability but also maintains grain yield. These findings provide a viable strategy for environmentally friendly rice production.