Plastics in soils threaten food security, health and the environment (FAO) |UN info

While plastic waste that litter the beaches and oceans attract attention, the FAO report entitled Evaluation of agricultural plastics and their sustainability: a call to action suggests that the land we use to cultivate our foods arecontaminated by even larger quantities of plastic pollutants.

"Sols are one of the main receivers of agricultural plastics and we know that they contain larger quantities of microplastics than the oceans," said Maria Helena Semedo, Deputy Director of FAO.

Surprising figures

"Each year we have 12.5 million tonnes of plastic products that are used in plant and animal production," said the deputy director of the climate change, biodiversity and environmental office at FAO, ZitouniOuld-Dada, at the microphone of UN info.

"And this is an almost equivalent amount of the 11 million tonnes that are rejected in the form of marine waste.And to this is also added to almost 37 million tonnes used in food packaging, "he added.“The largest users of plastic products are the agriculture and livestock sectors that consume about 10 million tonnes per year and it is an important figure because it is about 3% of world productionplastic ".

Fishing and aquaculture are also responsible for 2 million tonnes and forestry is responsible for 0.2 million tonnes of plastic products.

The report indicates that Asia is the largest user of plastics in agricultural production, representing almost half of the world use.In addition, in the absence of viable alternatives, the demand for plastic in agriculture can only increase.

While the demand for agricultural plastic continues to increase, Ms. Semedo stressed the need to better monitor the quantities that "flee in the environment from agriculture".

© FAO/Luis TatoUne femme arrose le sol qu'elle cultive à Amudat, en Ouganda.

Weigh up the risks

Since their appearance in the 1950s, plastics have become omnipresent.In agriculture, plastic products contribute greatly to productivity, for example by covering the soil to reduce weeds;The nets that protect and stimulate plant growth, extend crop seasons and increase yields;and tree protections, which protect sowing and young animal plants, help create a microclimate conducive to growth.

"These are important opportunities for farmers," says Mr..Ould-Dada."There is also the right factor in reducing water demand.We find that the average efficiency of water use for crops in several regions in China, for example, would have increased by almost 25% compared to the control which is carried out without mulching, "he explains.

However, of the approximately 6.3 billion tonnes of plastic produced before 2015, almost 80% have never been properly eliminated.

If the effects of large plastic objects on marine fauna have been well documented, microplastics released during their disintegration potentially affect whole ecosystems.

Bad plastic management at the end of life

Unsplash/Erwan Hesry12,5 millions de tonnes de produits plastiques sont utilisés dans la production végétale et animale

Unfortunately, the very properties that make plastics so useful create problems when they reach the end of their useful life.

"A bad design, poor selection, use and management of this end of life of plastic products has harmful effects on terrestrial and aquatic ecosystems," explains M.Ould-Dada.

"Often farmers do not have the sufficient means to select, use and manage or recover these products in order to properly eliminate the plastic from the fields," he said."And they often do not also have access to the tools necessary for good management of these products at the end of their lives".

Therefore these plastics are often abandoned or burned in the fields "which leads to soil contamination".

The introduction of biodegradable plastic films is complex due to the lack of standardization of their effectiveness and degradability."We have data that comes from China, for example, which have shown that the accumulation of plastic in the soil up to 240 kg per hectare can reduce crop yield by 11 to 25%".

Another important factor: the production of plastics contributes to greenhouse gas emissions and therefore climate change.

Microplastics - size less than 5 mm - were found in human excrement and placenta, and were transmitted to the fetus by their pregnant mother.

If most scientific research on plastic pollution has focused on aquatic ecosystems, FAO experts believe that agricultural soils receive much larger quantities of microplastics.

"This report is a strong call for coordinated and decisive action to facilitate good management practices and slow down the disastrous use of plastics in all agricultural sectors," said Maria Helena Semedo.

Main recommendations

Unsplash/Naseem BurasLa pollution plastique est devenue omniprésente dans les sols agricoles, menaçant la sécurité alimentaire, la santé des populations et l'environnement.

In the absence of viable alternatives, it is impossible to prohibit plastics - and there is no miracle solution to eliminate the damage they cause.

The report however identifies several solutions based on the model ‘refuse, redefine, reduce, reuse, recycle and recover’.

M.Ould-Dada suggère des produits et pratiques alternatives qui pemettent d'éviter l'utilisation de plastique.Thus, coverage crops and biomass can replace plastic mulching films.Or, reusable and durable products, for example, the glass and durable plastic covers for greenhouses, can reduce the use of plastic.

FAO continues to develop and also help farmers be aware of this pollution in fields and its consequences and alternative solutions to adopt."It is very important for sustainable development in general and for food security in the long term," concluded M.Ould-Dada.