Agricultura and plastics. Part 1.

On Tuesday, January 24, we will give the first training session dedicated to agriculture and plastics and that has been included in the training program MENORCA PRESERVADA.

This training is contemplated in Action Plan for the reduction of plastic pollution in Menorca 2030, drafted in 2021, by the IUCN and our alliance.

The first session will be dedicated to explaining the legal obligations of the agricultural sector in relation to plastic waste and the effects of plastic pollution on nature, human health and the economy and the contribution of agricultural activity to this environmental problem.

Regarding the regulations in relation to plastic waste, Law 3/2019, of January 31, Agrarian of the Balearic Islands is the one that contains most of the mentions in its articles 8, 16, 31, 40, 54 and 55. On the other hand, the Pla Sectorial Director of Prevention and Management of non-perillous waste of Menorca 2019-2025 in its chapter X speaks of plastic waste from agriculture.

Agricultural plastics,

with an LER code of 02 01 04, include waste agricultural plastics, silage bags, fertiliser bags and compound feed, plasticised hay bale twine, plastic belts for covering silage bales, drip irrigation pipes, greenhouse plastics, mini-tunnels, mulches, etc. In Menorca in 2021, more than 340 tons of agricultural plastics were generated. The agricultural plastics collected are not recycled and go directly to the landfill of Milà due to the large number of improper ones they present.

According to a FAO study, on a global scale between 3 and 5% of the production of plastic waste is due to agriculture and among the plastic waste from agriculture the most frequent are films and plastics for irrigation and drainage . This study also estimates that up to 3,500 kg of greenhouse film per hectare, 400 kg/ha of irrigation pipes and about 200 kg/ha of mulching plastic can be found.

On the other hand, a wide variety of plastics are used in agriculture (low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), ethylene copolymers and polar monomers (vinyl acetate (EVA), butyl acrylate (EBA)), plasticized polyvinyl chloride (PVC) and polypropylene (PP). as well as plastic materials in the form of rigid plate (bisphenol A polycarbonate (PC), methyl polymethacrylate (PMMA), etc.) and which are difficult to recycle.

The main sources of contribution of agricultural plastics to the environment are:

1. If sewage sludge and compost are used as fertilizers.

2. Degradation or breakage of plastic plastics, films and plastic equipment.

3. Irrigation with wastewater containing microplastics.

4. The use of encapsulated fertilizer and seeds coated with plastics.

Once released into the environment, macro and microplastics can:

1. Be transported by the wind to the environment, rivers or streams and even to the sea if the fields are close to the coast.

2. Runoff can transport macroplastics and microplastics from agricultural soil through river systems to the sea.

3. Biota can move microplastics deep into the soil. For example, through tunnels and ingestion by earthworms.

A study on microplastics in the environment of the Institut d'Estudis Catalans, gives some interesting data on the contribution of agricultural activity in plastic pollution. Among other data, it is offered that compost can contain between 2.38 and 180 mg of microplastics per kilogram or that the use of sewage sludge as fertilizer can provide between 1,500 and 24,000 particles of microplastics per kilogram.  Irrigation with treated water is another factor in providing microplastics and can vary between 1,000 and 627,000 particles per m3. 

In addition, plastics are sensitive to environmental factors such as wind, ultraviolet radiation or temperature. These factors affect its breakage and degradation. The important influence of the winds on the island, with episodes of strong Tramuntana wind and the irregular rainfall regime, with episodes of intense rainfall in autumn mainly, are factors to be taken into account. Temperatures on the island are mild, although in summer they can exceed 40ºC, a fact that can also favor greater photodegradation of plastics. Another characteristic fact of the island, is its size and the large land cover dedicated to agricultural land (almost 50% of the total), which is often found close to the coast and, therefore, there may be a migration of plastics from the field to the coast.