You are here

Microplastics and crops

There are many ways we use plastic in agriculture – greenhouses, plastic mulch, tile lines, seed bags, and more. On the farm, ultraviolet light, temperature and wind will eventually break down the plastic into tiny particles called microplastics that can remain in the soil forever or move to an aquatic environment.

Kansas State University crop physiologist Mary Beth Kirkham conducted an experiment on wheat that showed the presence of tiny particles of plastic in the soil caused water to pool up on the surface. The flooded conditions prevented oxygen from getting to the plant roots, but she also discovered another adverse effect.

"If there are contaminants in the soil along with the microplastics, then the plants will take them up and that’s what I saw in my experiment. The wheat that I studied took up a lot more cadmium with the microplastics in the soil than without the microplastics," says Kirkham. "And then of course, the microplastics because the wheat was flooded, it closed the stomata, which are little small pores on the leaves on the plants and the plants didn’t grow and the plants died."

Much more research needs to be done. But in the meantime, Kirkham has some recommends for reducing the amount of plastic in the soil.

"The solutions I see would be to go back to some of the original materials that were used before plastics were used, for example, glass greenhouses. Plastic greenhouses only last about four years but glass greenhouses will last a lot longer than that. And then also we can use ceramic tiles," she says. "Instead of using plastic mulches we might go back to some of the original mulches which were leaves, straw or paper."