Microplastic invasion: Oceans, soil and food?

Guusta Noordam is an asparagus farmer in Woubrugge in the Netherlands. Every year she harvests some 20 tonnes of the prized vegetable, a local Dutch staple.

Like many other crops, plastic has become a central component to how asparagus is produced. It grows in trenches, covered with black plastic sheets. 

"This is necessary to keep the asparagus white. As soon as the asparagus is exposed to the sun, it turns a little purple, pink and then green," Guusta explains.

The plastic sheet is also reversible and depending on the season and weather, it can be turned around. The white side keeps the asparagus in cool conditions, while the black side retains the warmth. 

"We would have a hard time doing our job without plastic film," she says. It would mean hiring more people to harvest twice a day. 

"To my knowledge, there is no alternative to plastic film, but if there was a good alternative with the same results, we would be happy to use it," she adds. 

Plastics have infiltrated every aspect of our lives, including the way our food is grown. T hey're used extensively in agriculture: in greenhouses and mulch film, but also as coatings on fertilisers, pesticides and seeds. Plastics have helped increase crop yields but at a steep environmental cost, as they degrade and break down into tiny fragments of microplastic.

And it doesn’t end there. Sewage sludge, the byproduct left behind after wastewater is cleaned, is commonly used as fertiliser and sprayed onto farmland, even though it contains high concentrations of microplastic particles. 

According to recent estimates, between 1 and 6 million tonnes of microplastics can now be found in agricultural soil, although the impact of such levels is not yet fully understood.