How plastic pollution is deteriorating soil quality for agriculture

Agricultural soils may receive greater quantities of microplastics than oceans, indicates a recent research by the United Nations Environment Programme (UNEP) and the Food and Agriculture Organization of the United Nations (FAO).

Plastic leaches into soils around the world, reducing its quality and often entering the food chain. Experts are raising the alarm about what they call an invisible threat to the world’s food systems.

“Our accounting systems don’t assign a value to healthy soil, so incentives to keep soil healthy are weak,” said Mahesh Pradhan, Coordinator of UNEP’s Global Partnership for Nutrient Management. “Plastic products on farms are really part of the toxic trail of economic growth.”

Plastics in soils is a global problem that usually goes hand-in-hand with intensive agriculture. Experts say it’s present everywhere from Asia to North America to Africa. Stemming the tide will be crucial in the coming years. Researchers estimate that more than 8.3 billion tons of plastic has been produced since the early 1950s and the global volume of plastic waste continues to grow.

The report shows that global food security is being compromised by soil pollution.

Much of the plastic that finds its way into soil is of the single-use variety, says Pradhan. Frequent sources include plastic mulch films, which are used around plants to keep the soil moist, and plastic-encapsulated, slow-release fertilizers, he says. Other plastic products include films for greenhouses and silage, shade and protection nets, and drip irrigation, says Lev Neretin, from the Office of Climate Change, Biodiversity and Environment at FAO.

Several of these plastics break down into particles smaller than 5mm in size, known as microplastics, before disintegrating further into nanoparticles, which are less than 0.1 micrometre in size. These can then leech into the soil and groundwater systems.

Health Impact

Some studies suggest degraded plastics can accumulate in the food chain. While more research is needed on the health impacts, Neretin says studies have identified microplastics in human organs, most recently in the brain.

Possible Solution

Pradhan says the entire farming sector needs to become more efficient and reuse plastics.

That is happening in many places, says Neretin. Some 60 countries have developed what is known as extended producer responsibility schemes for the management of empty pesticide containers, which place the onus on manufacturers to treat or dispose of their products at the end of their life cycle. Some schemes also collect and recycle a wider range of agricultural plastics.

Some manufacturers have also turned to innovative materials, such as biodegradable plastic, which they claim can safely be broken down by microbes and turned into biomass or water. Ultimately, though, experts say this is an issue that won’t be solved by any one group on its own.

 

[This story is a part of ‘Punascha Pruthibi – One Earth. Unite for It’ awareness campaign by Sambad Digital]