Recovery of agricultural plastics is technically and economically difficult:

• Contamination: Used mulch films carry substantial soil and plant residue, which raises cleaning costs and lowers recyclate quality.
• Fragmentation: Thin films tear during removal, leaving fragments in the field.
• Small-format components: Plant clips, ties and labels are dispersed and labour-intensive to recover.
• Remote placement: Tree guards and sleeves in forestry are frequently left in place because collection is impractical.

Where retrieval is incomplete, conventional polyolefins persist and fragment. Soil-biodegradable materials target precisely these use cases, offering:

• No separate retrieval step
• Lower agricultural plastic waste and lower collection labour
• Partly bio-based content in some grades (e.g., 10% bio-based carbon in Bio-Flex® FX 1135)
• Biodegradation in the same environment where the product is used

Bio-Flex® is FKuR’s family of biodegradable bioplastic compounds. It includes industrially compostable, home-compostable and soil-degradable grades, all designed to run on conventional extrusion and injection-moulding equipment. The soil-degradable grades for agriculture, horticulture and forestry include:

• Bio-Flex® FX 1135: Certified soil-degradable compound (TÜV Austria OK biodegradable SOIL) for mulch films and agricultural films. Processed by blown-film extrusion, with film thicknesses down to 8 µm. Contains 10% bio-based carbon (ASTM D6866).
• Bio-Flex® N 21310: Soil-degradable grade for agricultural films, with balanced mechanical properties.
• Bio-Flex® N 31310: Soil-degradable grade with high puncture and tear resistance, aimed at agricultural films and plant labels. Certification in process.
• Bio-Flex® N 25370: Certified soil-degradable grade (TÜV Austria OK biodegradable SOIL) with high density and excellent flexibility, for injection moulding and profile extrusion. Developed for tree guards and growth sleeves in forestry and agriculture.
• Bio-Flex® N 45261: Grade for clips, plant stakes and pots.

According to FKuR, all Bio-Flex® N grades degrade in soil without leaving residue and do not produce persistent microplastics. This makes them suited to products that remain in nature after use or cannot be collected again.

A common misconception is that “biodegradable” means a plastic simply disappears. Visual disappearance is not the criterion. The criterion is mineralisation: conversion of the polymer’s organic carbon by microorganisms.

Polymer + O₂ → (microbial action) → CO₂ + H₂O + Biomass

The process typically proceeds in two stages:

• Depolymerisation: extracellular enzymes from soil bacteria and fungi break polymer chains into oligomers and monomers.
• Assimilation and mineralisation: these low-molecular-weight fragments are taken up by microorganisms and metabolised into CO₂, water and new biomass.

Two-stage biodegradation of a soil-biodegradable plastic

Soil-biodegradability standards set a quantitative threshold. For example, EN 17033, the European standard for biodegradable mulch films, requires at least 90% conversion of the material’s organic carbon into CO₂ within a maximum of two years. The test is run in standardised soil at 20–28 °C following ISO 17556. Because carbon is tracked all the way to CO₂, rather than to visual disappearance, this approach addresses the question of persistent microplastics directly.

The word “biodegradable” on its own is not a technical claim. For commercial use, it must be tied to a defined test method, pass criteria and an independent certification.

Bio-Flex® FX 1135 and Bio-Flex® N 25370 carry TÜV Austria’s OK biodegradable SOIL certification, and certification of further N-series grades is in progress. The OK biodegradable SOIL scheme assesses three things:

• Biodegradation: chemical breakdown of the polymer in soil
• Ecotoxicity: no negative effect on plant growth
• Heavy metals: content within defined limits

For agricultural mulch films specifically, EN 17033 is the dedicated European standard. It combines soil biodegradation, ecotoxicity (plants, earthworms, soil microorganisms), composition limits and film performance requirements such as tensile strength and light transmission.

When specifying a product, always check which certificate applies to the exact grade, and whether it covers the granulate or the finished product.

Certification replaces a generic “eco-friendly” message with a verifiable, auditable specification.

Soil biodegradability does not mean uncontrolled degradation. The product must first do its job:

A mulch film must retain its mechanical and barrier function for the full crop cycle to deliver weed suppression, moisture retention and soil-temperature benefits.

• A plant clip must hold sufficient mechanical integrity for as long as the plant needs support.
• A tree guard must protect the sapling through its critical establishment phase.

Formulation is what controls this balance. FKuR notes that the good moisture resistance of Bio-Flex® keeps mulch film from breaking down too quickly while it covers the field.

Only after the useful service life should biodegradation become the dominant process. Real-world biodegradation rates depend on several interacting variables:

• Material: polymer composition and formulation
• Product design: wall thickness and film gauge
• Soil: moisture, oxygen availability, nutrient content and microbial activity
• Climate: temperature profile and seasonal conditions

This is why application-specific material selection and field validation are essential. There is no single “biodegradable plastic” that suits every crop, climate and soil.

Sustainability must work economically to scale. With conventional agricultural films, the end-of-life chain is long and costly:

Use → Collect → Clean → Transport → Recycle / Dispose

For suitable applications, soil-biodegradable materials shorten the pathway to:

Use → Incorporate into soil → Biodegrade

End-of-life pathways for agricultural film

The comparison should therefore be made on total cost of ownership, not resin price alone: removal labour, transport, cleaning and disposal or landfill fees all count. The outcome depends on the product, its certification, local farming practice and regulation, and needs to be evaluated case by case.

Soil biodegradability is not a licence for “single-use without responsibility”. The guiding principle is to match the material to its realistic end-of-life pathway:

• Make → Use → Dispose is the linear model the industry is moving away from.
• Make → Use → Recover → Recycle → Reuse is the circular model, preferred wherever collection and recycling are efficient.
• Make → Use → Biodegrade → Return carbon to the biological cycle is the soil-biodegradable pathway, suited to applications where physical recovery is impractical.

Matching material to end-of-life

If a product can be efficiently collected and recycled, recycling may be the better choice. But for a small component that is practically impossible to retrieve from soil, designing for certified soil biodegradability is the more rational engineering decision. Used this way, soil-biodegradable plastics complement mechanical recycling and compostable materials rather than competing with them.

India’s large and diverse agricultural base, spanning row crops, plantations, horticulture, nurseries and forestry, offers significant scope for soil-biodegradable materials:

• Mulch films
• Nursery products
• Plant clips
• Tree protection
• Horticultural products
• Agricultural twines and support materials

Photo by Kouji Tsuru on Unsplash

The goal is not simply to swap conventional plastic for biodegradable plastic. It is to identify the points in the value chain where collection is difficult, recycling is impractical, and soil biodegradation delivers a genuine lifecycle advantage. That is where material science creates measurable value.

SKYi FKuR Biopolymers Pvt. Ltd., Pune, is FKuR’s local contact for India, providing access to the Bio-Flex® portfolio and FKuR’s application expertise.

Grade selection follows a structured, application-led sequence:
Application → Processing technology → Required mechanical performance → Service life → Soil and climatic conditions → End-of-life requirements

Application-led grade selection

The right material comes from the right questions, because there are different materials for different environments and different jobs.