Researchers, including one of Indian origin, have found that the plastic mulch used to support the growth of strawberries sheds large quantities of plastic mulch fragments. These particles have been shown to negatively impact soil qualities, casting doubt on the long-term viability of their use. The findings from the survey are likely to apply worldwide to plastic use in agricultural production.
“What we are seeing is a huge quantity of macroplastic plastic material — particles bigger than 5mm across — being shed where the mulch is used to enhance strawberry production. These can remain in the soil for decades or longer,” said postdoctoral researcher Dr. Ekta Tiwari from the Sistla group at California Polytechnic State University.
Tiwari presented the work at the ongoing Goldschmidt geochemistry conference in Lyon, France. Plastics, such as polyethylene, are increasingly used in agriculture, for example, in polytunnels. Plastic mulch films are extensively used in agriculture, where they provide a range of benefits.
They are tucked in around the base of the plant, which can help control weeds and pathogens, reduce water evaporation, and prevent soil splashing on fruit (which is particularly important for strawberries). The mulch is applied in rows and then removed after the crop’s seasonal production is complete. However, even careful land stewardship by farmers does not ensure all the plastic is removed because fragments get left behind and adhere to the soil during removal.
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