Effects of PBAT/PLA biodegradable film mulching on greenhouse gas emissions in rain-fed maize farmland of Northeast China

Plastic film mulching can effectively increase soil temperature, retain moisture, and enhance crop yield and quality. However, long-term application might pose risks of increased greenhouse gas (GHG) emissions and residual film pollution. Biodegradable film provides a crucial solution to alleviate farmland plastic pollution, but it remains unclear whether biodegradable film can simultaneously enhance crop yields and reduce GHG emissions. Thus, a two-year field experiment was conducted in rain-fed maize farmland of Northeast China. This field experiment included four treatments: BM1 (0.006 mm-thick biodegradable film), BM2 (0.010 mm-thick biodegradable film), PM (0.010 mm-thick traditional plastic film), and CK (non-mulching control). Results indicated that film mulching increased cumulative CO2 emissions by improving soil temperature and moisture. BM1 and BM2 achieved lower cumulative CO2 emissions than PM. N2O emissions were mainly concentrated in the emergence and jointing stages, whose peaks and cumulative values were reduced by film mulching. BM1 and BM2, however, had higher cumulative N2O emissions than PM. All treatments were CH4 sinks, and mulching treatments showed low soil CH4 absorption compared to CK. Additionally, mulching treatments increased maize yield, GWP and GHGI by 4.19 % to 15.89 %, 8.52 % to 52.20 % and − 0.06 % to 45.93 %, respectively, compared to CK. PM showed the highest GWP and GHGI. All mulching treatments improved the net ecosystem economic budget, with increases of 3.03–3.08 thousand CNY ha−1 and 0.35–1.39 thousand CNY ha−1 in 2022 and 2023, respectively, compared to CK. Biodegradable film treatments had higher net ecosystem economic budgets than traditional plastic film treatment. Overall, the biodegradable film can be used to replace traditional plastic film to enhance maize yield while minimizing residual film pollution and GHG emissions in the experimental region. © 2024 Elsevier B.V.