Strawberry Production Can Lead To Plastic Pollution: Cal Poly Study
NEW YORK, NY (IANS) – Researchers, including an Indian American scientist, have discovered that the plastic mulch commonly used in strawberry cultivation releases significant amounts of plastic fragments. These findings raise concerns about the long-term sustainability of using plastic mulch due to its detrimental impact on soil quality. The implications of the study are likely applicable worldwide to the use of plastics in agricultural practices.
Dr. Ekta Tiwari, a postdoctoral researcher from the Sistla group at California Polytechnic State University, presented the study at the Goldschmidt geochemistry conference in Lyon, France. She highlighted the substantial release of microplastic particles, measuring over 5mm in size, when plastic mulch is utilized to enhance strawberry production. These particles can persist in the soil for decades or longer, posing a persistent environmental concern.
Plastics, including polyethylene, have increasingly found use in agriculture, such as in polytunnels. Plastic mulch films offer various benefits in agricultural applications. They are placed around the base of plants to control weeds and pathogens, reduce water evaporation, and prevent soil from splashing onto the fruit, which is particularly crucial for strawberries. The mulch is applied in rows and subsequently removed after the growing season.
However, even with careful land management practices, some plastic fragments inevitably remain in the soil after removal due to adherence. After years of annual plastic mulch application and removal, the researchers observed the accumulation of plastic fragments in farmland soils, even in well-managed fields.
The researchers focused on identifying microplastics, which are plastic pieces larger than 5mm. They discovered high concentrations of up to 213,500 microplastic particles per hectare on field surfaces alone (equivalent to 10,000 square meters). This count does not include sub-surface particles, which were not surveyed in the study. The researchers are currently analyzing soil samples for smaller microplastic particles, less than 5mm in size, and those findings are yet to be included.
The majority of these particles were found to be polyethylene. Preliminary results indicate that increasing levels of microplastic pollution correlate with decreased soil moisture content, microbial respiration, and plant-available nitrogen.
Dr. Tiwari emphasized that while plastic mulch offers benefits, they come at the expense of long-term soil quality. The removal of these particles from the soil is challenging and costly, making it difficult to mitigate their environmental impact once they accumulate.
She further highlighted the need to recognize that even enjoyable commodities like fresh strawberries can have environmental costs. Collaborating with manufacturers, the researchers aim to explore ways to mitigate these environmental consequences and reduce the negative impacts associated with plastic mulch use.