Recent research has unveiled the unanticipated environmental ramifications of plastic mulch, a popular tool in California’s strawberry cultivation. While advantageous in several respects, these plastic mulch fragments are challenging to remove completely, thereby leading to persistent soil plastic pollution. This study has triggered a collaborative effort among researchers and manufacturers to tackle these ecological concerns.
The study has drawn attention to an unexpected, significant source of plastic pollution – the California strawberry farms. Plastic mulch, widely employed to stimulate strawberry growth, has been detected to contribute substantial plastic debris to the soil. This occurrence, which detrimentally impacts soil health, brings the long-term sustainability of using plastic mulch into question. These findings potentially have worldwide implications for plastic usage in agricultural practices.
During their presentation at the Goldschmidt geochemistry conference held in Lyon, postdoctoral researcher Dr. Ekta Tiwari, from the Sistla group at California Polytechnic State University, pointed out, “We are witnessing a considerable quantity of macroplastic material—particles larger than 5mm—being shed where the mulch is used to boost strawberry production. These can linger in the soil for decades, if not longer.”
Plastic materials, including polyethylene, are finding increasing use in agriculture, for example, in polytunnels. Plastic mulch films are widely used in farming, offering multiple benefits. These films are wrapped around the plant base, helping control weeds and pathogens, reducing water evaporation, and preventing soil from splashing onto the fruit, especially crucial for strawberries.
The research found that plastic mulch, largely employed to foster strawberry growth in California, discharges significant plastic fragments into the soil. These fragments degrade soil quality and challenge the sustainability of plastic usage in farming. The problem intensifies as, despite diligent removal efforts, plastic mulch leaves fragments in the soil, causing plastic build-up over time.
This mulch is applied in rows and taken off once the seasonal crop yield is over. Yet, even thorough land management practices by farmers don’t ensure total plastic removal, as fragments stick to the soil during extraction. After years of annual plastic mulch application and extraction, researchers noticed plastic debris accumulation within farm soils, even in excellently managed fields. The researchers focused on macroplastics, which are plastic pieces larger than 5mm.
Tiwari added, “Our systematic survey of strawberry fields after the seasonal removal of this plastic film showed a pretty uniform distribution. We found up to 213,500 macroplastic particles per hectare on field surfaces alone. And this doesn’t include subsurface particles, which we didn’t survey. We’re currently analyzing these same soil samples for microplastics, smaller particles less than 5mm; these haven’t been included in our findings yet.”
Note: A hectare measures 10,000 square meters. To compare, an average professional soccer playing pitch is about 7,100 square meters, while an American football field measures 5,350 square meters.
Most particles are polyethylene, as identified using Fourier transform infrared spectroscopy. Preliminary findings indicate that as macroplastic pollution escalates, soil moisture content, microbial respiration, and plant-available nitrogen decline.
Dr. Tiwari stated, “The plastic mulch offers benefits, but at the cost of long-term soil quality. It’s challenging and expensive to extract these particles from the soil, so once they’re there, they remain indefinitely.”
Often, we think of strawberries as simply delightful treats. However, this study highlights that even something as enjoyable as fresh strawberries can have an environmental cost. Currently, we’re collaborating with manufacturers to explore ways to mitigate these costs.
Alternative options to polyethylene mulches do exist, such as biodegradable plastic mulches or natural mulches like straw, but these alternatives come with an economic cost. Nevertheless, the use of plastics in agriculture is increasingly regulated, as exemplified by the European Union’s guidelines found at https://environment.ec.europa.eu/system/files/2021-09/Agricultural%20Plastics%20Final%20Report.pdf
Professor Sean Schaeffer, Department of Biosystems Engineering & Soil Science, University of Tennessee, USA, commented:
“Plastics, especially plastic mulches, are essential to sustain agricultural production. They serve various purposes like retaining soil moisture, regulating soil temperature, and controlling weeds or pests. The use of agricultural plastic is growing worldwide, with California leading in the US. Research into the fate and transport of plastics in soil and water systems is relatively new, making studies like this crucial to understanding the extent of the plastic problem. We currently have limited knowledge about the distribution, size, and types of plastic in soils in the largest states, both in land area and agricultural production.”
This comment is independent; Professor Schaeffer was not part of this work.
This work is ongoing and is yet to be peer-reviewed. The researchers are currently assessing the level of microplastic pollution (particles smaller than 5mm) left by plastic mulches. This study provides initial data to understand the scope of plastic pollution in the U.S. agricultural system and can assist in refining land management practices by evaluating the biogeochemical consequences of plastic accumulation in agricultural soils.
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Frequently Asked Questions (FAQs) about Plastic Pollution in Strawberry Farming
What is the main source of plastic pollution in Californian strawberry farms according to the study?
The main source of plastic pollution in Californian strawberry farms, as per the study, is plastic mulch. This tool is commonly used to promote strawberry growth, but it sheds significant amounts of plastic fragments into the soil.
What are the negative effects of plastic mulch usage in agriculture?
While plastic mulch does provide several benefits like weed and pathogen control, reduced water evaporation, and prevention of soil splashing onto the fruit, its usage leads to significant soil plastic pollution. This pollution adversely affects soil health, degrading the soil’s moisture content, microbial respiration, and plant-available nitrogen.
What alternatives to polyethylene mulches exist in agriculture?
Alternatives to polyethylene mulches include biodegradable plastic mulches or natural mulches such as straw. However, these alternatives can come with an economic cost.
How are the researchers trying to mitigate the environmental cost of plastic mulch usage in agriculture?
Researchers are collaborating with manufacturers to explore ways to reduce the environmental cost associated with plastic mulch usage. They are also studying the extent of microplastic pollution caused by plastic mulches, which can help improve land management practices by assessing the biogeochemical consequences of plastic accumulation in agricultural soils.
What is the significance of this research on plastic mulch usage in agriculture?
This research is crucial in understanding the extent of plastic pollution in agricultural systems, especially in large-scale farming states like California. The findings have potentially global implications for plastic use in agricultural practices and can help inform regulations around the use of plastics in agriculture. The study also provides baseline data to understand the extent of plastic pollution in the U.S. agriculture system and can help improve land management practices.
More about Plastic Pollution in Strawberry Farming
- Understanding Plastic Pollution
- California Strawberry Farming
- Role of Plastic Mulch in Agriculture
- European Union Regulations on Agricultural Plastics
- Biodegradable Mulch Alternatives
7 comments
biodegradable mulches all the way people! yes, it might be a bit more costly but what price do we put on our planet huh?
As a farmer, this is a real concern. We need alternatives that don’t harm the environment, but also don’t break the bank…
This is why regulation is so important! The environment always pays the price if we’re not careful. thanks for sharing this.
Wow, I had no idea strawberry farming could cause this much plastic pollution! Makes you think twice about that strawberry shortcake, doesn’t it?
Fascinating read! I’m intrigued to see the results on microplastic pollution once they complete the study.
Hey folks, let’s not forget the benefits of plastic mulch. But yes, we need to find a way to mitigate the negatives. Let’s hope those researchers and manufacturers come up with a solution soon.
Sigh. It seems like everything has an environmental cost these days, even our food. Time to rethink our agriculture methods maybe?