We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Possible hazards from biodegradation of soil plastic mulch: Increases in microplastics and CO2 emissions
Summary
Researchers conducted an 18-month experiment to study whether biodegradable plastic mulches actually break down fully in soil or leave behind microplastic fragments. They found that the biodegradable mulches did generate microplastics and also increased soil carbon dioxide emissions compared to conventional mulch. The study raises questions about whether biodegradable mulches are truly more environmentally friendly than standard plastic film when microplastic generation and carbon release are considered.
Biodegradable mulches are widely recognized as ecologically friendly substances. However, their degradation percentage upon entering soils may vary based on mulch type and soil microbial activities, raising concerns about potential increases in microplastics (MPs). The effects of using different types of mulch on soil carbon pools and its potential to accelerate their depletion have not yet well understood. Therefore, we conducted an 18-month experiment to investigate mulch biodegradation and its effects on CO emissions. The experiment included burying soil with biodegradable mulch made of polylactic acid (PLA) and polybutylene adipate terephthalate (PBAT), and control treatments with traditional mulch (PE) and no mulch (CK). The results indicated that PE did not degrade, and the degradation percentage of PLA and PBAT were 46.2% and 88.1%, and the MPs produced by the degradation were 6.7 × 10 and 37.2 × 10 items/m, respectively. Biodegradable mulch, particularly PLA, can enhance soil microbial diversity and foster more intricate bacterial communities compared to PE. The CO emissions were 0.58, 0.74, 0.99, and 0.86 g C/kg in CK PE PLA, PBAT, respectively. A positive correlation was observed between microbial abundance and diversity with CO emissions, while a negative correlation was observed with soil total organic carbon. Biodegradable mulch enhanced the transformation of soil organic C into CO by stimulating microbial activity.
Sign in to start a discussion.
More Papers Like This
Are biodegradable mulch films a sustainable solution to microplastic mulch film pollution? A biogeochemical perspective
This review asks whether biodegradable mulch films are truly a sustainable alternative to conventional plastic films used in agriculture. Researchers found that biodegradable microplastics may actually accumulate more readily in soil than traditional microplastics because they require specific conditions to fully break down. The study warns that biodegradable films could alter soil carbon and nitrogen cycling, microbial communities, and greenhouse gas emissions in ways not yet fully understood.
The role of biodegradable plastic mulches in soil organic carbon cycling
This review examines the role of biodegradable plastic mulches in soil organic carbon cycling as an alternative to conventional polyethylene mulches, which shed microplastics into agricultural soils. Biodegradable mulches offer potential environmental benefits but their long-term soil impacts are still being studied.
The long-term uncertainty of biodegradable mulch film residues and associated microplastics pollution on plant-soil health
This study investigated the long-term effects of biodegradable mulch film residues and their associated microplastics on soil health and plant growth. Researchers found that as biodegradable films break down faster than conventional plastics, they may actually generate more microplastics in a shorter timeframe. The results raise concerns that biodegradable mulch films, often promoted as eco-friendly alternatives, could pose their own risks to agricultural soil ecosystems.
Microplastics from conventional and biodegradable mulch films alter microbial necromass accumulation and organic carbon sequestration in farmland soils
Researchers compared how microplastics from conventional polyethylene and biodegradable mulch films affect soil organic carbon storage over 120 days. They found that both types of microplastics altered microbial activity and reduced the accumulation of microbial-derived carbon in soil. The study suggests that even biodegradable plastics, once broken into microplastics, may interfere with soil carbon sequestration in farmland.
Biodegradable Film Mulching Increases Soil Carbon Sequestration and Microbial Network Complexity in a Long-Term Field Study
Scientists studied biodegradable plastic mulch (the plastic sheeting farmers use to cover soil) and found it helps soil store more carbon and support healthier microbial communities compared to regular plastic mulch. However, the biodegradable plastic still breaks down into microplastics in the soil, raising questions about long-term environmental effects. This matters because while biodegradable farm plastics may help fight climate change by storing carbon, we still need to understand how the microplastics they leave behind might affect our food system.