4 January 2022

Pollution, there is more plastic in agricultural land than in the oceans

Contamination and plastic pollution in soils are even greater than those affecting the seas and oceans.

FAO produced the first report on the use of plastics in agri-food systems. Pollution is pervasive, especially in Asia. The solutions revolve around the “6Rs”: reject, redesign, reduce, reuse, recycle and recover. It is essential to invest in the search for alternative products

by Emanuele Isonio


Sheets for mulching and to enclose hay bales, bags for fertilizer, tubs for bulbs, irrigation pipes, covers for greenhouses, straps for tying plants, bottles of pesticides, protection nets. All fundamental tools for the agricultural world. As many examples of how plastic and consequently its residues are now pervasive in fields all over the world. Much more than imagined. If the waste dispersed at sea and the immense islands of plastic that roam the oceans have made – rightly – news, they are not the main threat to food, environmental and human safety.

The first global report on plastics in soils

“The land we use to grow our food is subjected to much greater pollution from plastic contaminants.” This is stated in the new FAO report, “Evaluation of agricultural plastics and their sustainability: a call to action”. The first that the UN body dedicates to the problem. Moreover with a planetary vision.

According to data collected by the agency’s experts, agricultural supply chains use 12.5 million tons of plastic products every year. Another 37.3 million tons are used in food packaging. The main users are represented by the different segments of agricultural production and livestock, with a total of 10.2 million tons per year. This is followed by fishing and aquaculture with 2.1 million tons and forestry with 200 thousand tons.

Stima delle quantità annue di plastica utilizzata nei terreni agricoli mondiali divise per tipologie di prodotto. FONTE: Assessment of Agricultural plastics and their sustainability. FAO, 2021

Estimation of the annual quantities of plastic used in world agricultural land divided by product types. SOURCE: Assessment of Agricultural plastics and their sustainability. FAO, 2021.

Bad forecasts

At a territorial level, the largest users of plastic in agriculture are the Asian countries: they account for half of the global use. Rather understandable, given that well over half of the world’s population resides in that continent and is the area with the fastest economic development today. In the absence of viable alternatives, the demand for plastics is therefore bound to increase, there as in other areas.

According to FAO experts, for example, global demand for greenhouse, mulch and silage films will increase by 50%, from 6.1 million tonnes in 2018 to 9.5 million tonnes in 2030. Trends that make it essential to evaluate costs well and benefits of plastic.

Uso di teli plastici in agricoltura nelle diverse regioni mondiali. FONTE: Assessment of Agricultural plastics and their sustainability. FAO, 2021

Use of plastic sheets in agriculture in the various regions of the world. SOURCE: Assessment of Agricultural plastics and their sustainability. FAO, 2021

“This report serves as a strong call for coordinated and decisive action to facilitate good management practices and curb the disastrous use of plastics in agricultural sectors,” FAO Deputy Director-General Maria Helena Semedo said in the presentation of the report.

Environmental and health hazards

The greatest concern, as is the case with the pollution of seas and oceans, is directed in particular to microplastics. They are the greatest risk to human health, given their ability to enter the food chain through contamination of soil, air and water basins.

Ecco come la plastica entra in circolo negli ecosistemi terrestri e nella nostra catena alimentare. FONTE: FAO, 2021

This is how plastic enters the earth’s ecosystems and our food chain. SOURCE: FAO, 2021

At the root of the problem, in addition to the enormous use of plastic in agriculture, there is above all the difficulty of disposing of waste correctly.

Of the approximately 6.3 billion tons of plastic produced up to 2015, nearly 80% was not disposed of properly.

Once dispersed in the natural environment, the problems caused by that waste are many. The effects on marine fauna are now well known (Ispra recently calculated for example that 90% of the turtles ingested plastic). But in soil, as plastics begin to disintegrate and degrade, their impacts affect the cellular level. It is not only individual organisms that are involved but also, potentially, entire ecosystems.

“Microplastics, smaller than 5 millimeters in size, present specific risks to animal health,” the FAO report points out. “There is evidence of mother-to-fetus transmission of much smaller nanoplastics in rats. But recent studies have found traces of particles of microplastics in human feces and placenta.” Considering that 93% of global agricultural activities take place on earth, there is a clear need for further investigations in this area.

Durata media dei prodotti plastici utilizzati in agricoltura. FONTE: Assessment of Agricultural plastics and their sustainability. FAO, 2021

Average duration of plastic products used in agriculture. SOURCE: Assessment of Agricultural plastics and their sustainability. FAO, 2021

Reduce and replace

FAO itself is aware, like all the experts in the field, that eliminating plastic from agricultural activities tout court is a chimera. In many cases, the absence of viable alternatives makes it impossible to deprive oneself, at least in the short term. To reduce harm and abuse, the report identifies several solutions.

A strategy made up of 6Rs: Reject, Redesign, Reduce, Reuse, Recycle and Recover.

The main actions should be directed against plastic products where the potential for environmental damage is highest. FAO experts are placing fertilizers coated with non-biodegradable polymers and mulch sheets in particular on the dock.

The latter are among the most used products directly on the land for their ability to reduce the presence of pests, conserve humidity and ensure the preservation of an ideal microclimate. The UN agency report recalls that sheets and other plastic films, used for example to cover greenhouses, represent between 40 and 50% of the total plastic used in the agricultural supply chain. But their massive use leads to a huge disposal problem. In Europe alone, mulching films that are no longer usable reach 15 thousand tons. This is why their replacement with biodegradable and compostable specimens is one of the ways to go (their usefulness was officially recognized by the European Parliament as early as October 2017).

Classificazione delle plastiche per origine e biodegradabilità. FONTE: Assessment of Agricultural plastics and their sustainability. FAO, 2021.

Classification of plastics by origin and biodegradability. SOURCE: Assessment of Agricultural plastics and their sustainability. FAO, 2021.

Greenhouse sheets – FAO analysts suggest – could be replaced by more durable alternatives, such as glass or polycarbonate. While single-cycle products could be supplanted by preferring reusable options, such as rigid stackable drip boxes.

A bouquet of necessary actions

Upstream, however, the report shows the need to rethink the approach to agriculture, in order to develop more sustainable agricultural practices. Expressly indicated is conservation agriculture and the use of cover crops, which could be an absolutely natural alternative to mulching sheets.

Equally important is the need to establish standards for products and their labeling that favors their identification and traceability. Like the establishment of rules that extend the responsibility of the producer of plastic materials to the post-consumer phase, that is, its management once it has become waste. In this sense, FAO points out, “business models must be redesigned so that manufacturers or distributors of plastic products provide them as part of a service, rather than as a single transaction for the sale of goods”.

Produzione plastica globale e percentuale utilizzata nell'attività agricola. FONTE: Assessment of Agricultural plastics and their sustainability. FAO, 2021

Global plastic production and percentage used in agricultural activity. SOURCE: Assessment of Agricultural plastics and their sustainability. FAO, 2021

Investing in research

Finally, there is another area that the FAO report considers essential to ease the yoke of plastic in agriculture. Investments in research. In fact, there are important shadow cones in the knowledge of the problem on which light must instead be shed: the global flows of agricultural plastics, evaluations on their life cycle by comparing the plastics of fossil origin and those of vegetable origin, the paths and impacts of plastics of different sizes on agro-systems, the behavior and degradation rate of biodegradable products in different environments and conditions.

“The impacts of agricultural plastic pollution on microbiomes, soil and water quality and long-term soil productivity should also be investigated. In this way – the report reads – the general principles of good management practices can be quickly established through a voluntary code of conduct, while attempting the slower process of modifying and developing legally binding international agreements ”.