Compostable farm plastics can spike greenhouse gases in soil
Sarfraz W, Hussain M, Chen C, Chan CM, Khalid N
Soil Health
If you use biodegradable mulch film or compostable plant pots in a sandy garden bed, this research suggests it could trigger a surge in nitrous oxide, a greenhouse gas nearly 300 times more potent than CO2, while temporarily starving your plants of nitrate.
Scientists buried three types of biodegradable plastic in both sandy and clay-like soil and watched what happened over four months of wetting and drying, mimicking real weather cycles. One plastic type, called PHA, made soil microbes go into overdrive: they released far more carbon dioxide and, in sandy soil, a lot more nitrous oxide gas, while also using up nitrogen the plants would normally get. The other two plastics caused smaller, slower changes, showing that 'biodegradable' doesn't mean 'harmless' and that the effect depends heavily on what kind of dirt you're working with.
Key Findings
PHA-treated clayey soil showed cumulative CO2 emissions up to 464% higher than untreated soil, versus a 107% increase in sandy soil.
N2O emissions rose up to 4.2-fold in sandy soil under PHA treatment, while soil nitrate concentrations dropped by up to 59%.
Microbial biomass and carbon/nitrogen-acquiring enzyme activities increased 2-3 fold in clayey soil and 1-2 fold in sandy soil under PHA, with PBS causing more lasting microbial changes than PLA.
chevron_right Technical Summary
Biodegradable plastics used in farm mulch films break down differently depending on soil type, and one common type (PHA) causes big spikes in greenhouse gas emissions and disrupts nitrogen availability, especially in sandy soils, meaning 'compostable' plastics aren't automatically soil-friendly everywhere.
Abstract Preview
Original paper
Soil texture controls bioplastic-induced greenhouse gas emissions and carbon-nitrogen cycling in agricultural soils.
Bioplastics (BPs) are increasingly used in agriculture, yet their behavior in soil and effects on carbon (C) and nitrogen (N) cycling depend strongly on soil conditions. This study evaluated the ef...
open_in_new Read full abstractAbstract copyright held by the original publisher.
Was this useful?
Want to tell us more? (optional)
Thanks for the note!
Something went wrong — please try again.
Too many submissions. Try again in an hour.
Gene editing removes 97% of celiac-triggering proteins from bread wheat
It could mean that people with celiac disease — roughly 1 in 100 worldwide — may one day safely eat bread made from real wheat, without sacrificing the taste...
Composting is the controlled decomposition of organic materials—such as plant waste, food scraps, and manure—into a nutrient-rich amendment that improves soil fertility and structure. For plant science, compost is significant because it enhances soil microbial communities, increases nutrient
arrow_forward Explore topic