The use of support and binding elements in agriculture, particularly in greenhouses made of polypropylene (PP), is essential for crop cultivation. However, its disposal poses a significant challenge. If not separated at the source, these materials often end up mixed with other agricultural waste at treatment facilities.
In the municipality of El Ejido (Almería), the waste treatment facility Servicios Ambientales Las Chozas (SACh) manages approximately 60,000 tons of agricultural waste per year, from which 12,000 tons of compost are obtained. This process returns essential nutrients and microbiota to the soil, completing a natural cycle in which the soil recovers essential elements.
However, during composting, PP plastic elements must be removed, adding costs and increasing the risk of persistent microplastic residues accumulating in the final compost.
A Sustainable Solution – Bioplastics
To tackle this challenge, Bayer CropScience, in partnership with Novamont Iberia, tested biodegradable and compostable materials for plant binding and support. Instead of plastic twine and clips, they used products made from Mater-Bi®, a biopolymer developed by the Italian company Novamont, derived from renewable sources and certified according to the European standard EN 13432.
According to Alejandro Caravaca, Head of EMEA Veg R&D Sustainability and Outreach at Bayer CropScience, the goal was to find an alternative to conventional plastic materials to enable more sustainable end-of-life management of agricultural waste. Over one year, biodegradable twine and clips were tested across more than 80 hectares of experimental fields in Spain.
The trials covered various crops and growing seasons, using black and natural-colored twine produced by SiCOR and clips from the Agriculture division of ARaymond. Novamont supplied the base material, Mater-Bi®.
Test Results
The objective of the tests was to assess the strength and performance of these new materials in greenhouse environments, particularly for intensive pepper cultivation. Their resistance to mechanical stress, durability throughout the growing cycle, and ability to withstand extreme climatic conditions—such as high temperatures, humidity, and UV radiation—were evaluated.
According to Caravaca, “The twine and clips met the requirements for strength, resistance, and flexibility throughout the entire growing cycle. Additionally, they are easy to use, even with gloves, making plant binding more convenient for workers. Most importantly, these innovative solutions enable composting facilities to process crop residues with Mater-Bi® twine and clips without introducing microplastic contamination.”
Composting plant residues together with Mater-Bi® twine and clips proved to be an efficient way to prevent microplastic pollution. In some aspects, these new materials even exceeded expectations compared to conventional PP products.
To prevent microplastics from entering the soil and the environment, the use of biodegradable and compostable materials must increase. Collaboration between different companies and experts in the agricultural sector, as demonstrated in this project, has shown that innovative solutions exist to reduce the negative impact of plastics in intensive farming.
