A new study has found switching from conventional plastic film to degradable film mulching in dryland agriculture significantly increases soil carbon storage, improving climate mitigation and environmental sustainability.

Plastic film mulching has long been used to boost crop yields by improving water retention and soil temperature, especially in arid regions but its non-degradable nature contributes to persistent plastic residues that damage soil health.

Hackett Professor Kadambot Siddique, from The University of Western Australia’s Institute of Agriculture, and an international team of researchers co-authored the study published in Nature Communication.  

Researchers compared how plastic film mulching and degradable film mulching affected soil organic carbon storage across dryland systems.

Drawing on multi-site fieldwork and mesocosm experiments across China, the research addressed a knowledge gap in the global push to transition away from traditional plastic mulching.

By identifying the microbial pathways involved, the study improved understanding of how soil carbon cycles respond to different land management practices.

Results showed that while plastic film mulching reduced soil organic carbon, degradable film significantly boosted carbon storage, particularly through enhanced microbial activity in soils.

“This shows that degradable mulching not only avoids the long-term pollution caused by plastic film, but also actively improves soil carbon storage,” Professor Siddique said.

The research highlights the importance of studying subsoil layers, which contain the majority of global soil organic carbon but are often overlooked.

“This work provides real-world evidence that degradable mulching is a viable alternative, environmentally and agronomically."

"It supports the global shift toward farming systems that are productive, climate-smart and free of long-term plastic pollution.”