Plastic mulch films help farmers control weeds, retain soil moisture, and manage soil temperature. They are widely used for vegetables, fruit, and row crops because they support more stable growing conditions.
The problem comes after harvest. Thin film can tear during removal, leaving pieces mixed with soil, roots, and crop waste. Once the film becomes dirty and damaged, it is difficult to collect and recycle.
Biodegradable agricultural films offer another option for some short-term mulch applications. Soil-biodegradable films are designed to last through the crop cycle and then break down through microbial activity under suitable soil conditions. How well this process works will vary with the film thickness, local climate, soil conditions, and required working life.
How Conventional Plastic Mulch Creates Waste After Harvest
Most conventional mulch film is made from polyethylene, or PE.
Farmers use PE film because it is light, flexible, and relatively low-cost. It helps retain soil moisture, suppress weeds, and keep soil temperatures more stable during the growing season.
However, thin PE film can stick to wet soil, wrap around roots, and tear during removal. Even when most of the film is collected, smaller pieces may remain in the field. These fragments can stay in the soil for a long time because PE does not biodegrade under normal farming conditions.
The scale of the issue is significant. The Food and Agriculture Organization of the United Nations estimates that about 12.5 million tonnes of plastic products are used each year in plant and animal production. It also notes that mulch films can be difficult to recover completely after use.
Recycling is not always a simple solution.
Used agricultural film is often mixed with soil, moisture, crop residue, and agricultural chemicals. This contamination makes the film heavier, harder to clean, and less attractive to recycling facilities.
Together, these factors make used PE mulch difficult to manage: some fragments remain in the soil, while the collected film is often too contaminated for efficient recycling.
What Is a Soil-Biodegradable Mulch Film?
A soil-biodegradable mulch film is designed to remain functional during the crop cycle and then break down through microbial activity in soil.
After use, a suitable film may be incorporated into the soil according to the manufacturer’s instructions. Its breakdown then depends on factors such as soil moisture, temperature, microbial activity, film thickness, and material formulation.
The word “biodegradable” does not mean that a film disappears quickly or that any product with this label can be left on farmland.
Three terms are often confused:
- Soil-biodegradable film:tested for biodegradation under soil conditions.
- Industrially compostable film:designed to break down in controlled commercial composting facilities.
- Oxo-degradable film:designed to fragment more quickly with the help of additives.
Fragmentation is not the same as full biodegradation.
A compostable packaging film is also not automatically suitable for agricultural mulch. The material, product standard, thickness, and test conditions must match the intended farming application.
How Do Biodegradable Agricultural Films Reduce Plastic Pollution?
They Reduce Persistent PE Residue
Conventional PE mulch is made to stay strong throughout the crop cycle. However, pieces left in the field after harvest can remain in the soil for a long time.
Soil-biodegradable mulch film is designed for a different outcome. After completing its working life, it can break down through microbial activity under suitable soil conditions.
This can reduce the long-term buildup of persistent PE residue.
However, the claim must be supported. The finished film should be designed and tested for soil biodegradation, not simply labeled “biodegradable.”
They Reduce Post-Harvest Film Removal
Removing conventional PE mulch often requires machinery, manual labor, or both.
Thin film can tear during collection, leaving some pieces buried in the soil or attached to crop residue.
When designed for soil biodegradation, a biodegradable mulch film may be incorporated into the soil after use according to the manufacturer’s instructions. This can reduce the need to collect and transport used film.
Field management is still important. Farmers need to confirm when the film should be incorporated, how it should be mixed into the soil, and whether it has completed its working life.
They Reduce Contaminated Plastic Waste
Used agricultural film can still be difficult to recycle after collection.
It is often mixed with soil, plant matter, moisture, and other residues. Cleaning and transporting this film may require more water, energy, and labor than local recycling systems can support.
Replacing selected short-life PE mulch with biodegradable plastic mulch can reduce the amount of contaminated film that must be collected, cleaned, and managed as waste.
This is especially helpful in areas with limited agricultural plastic recycling.
Where Do Biodegradable Mulch Films Make Sense?
Biodegradable mulch film is best suited to short-term crop applications where conventional PE film is difficult to remove cleanly after harvest.
Common uses include:
- vegetable production
- strawberries and selected fruit crops
- corn and other row crops
- one-season weed control
- short-term soil moisture management
Soil-biodegradable mulch film works well in these applications because it only needs to remain functional during one growing season. After the crop cycle is complete, the film can be incorporated into the soil and begin biodegrading under suitable conditions. This reduces the need to collect thin, damaged film from the field.
It is not suitable for agricultural products that must remain strong for long periods. Greenhouse covers, irrigation pipes, silage films, and protective nets may stay in use for months or years. If these products begin to weaken or biodegrade during service, they may fail to provide the protection, water delivery, or storage performance required.
What Controls Biodegradation in Soil?
A biodegradable mulch film will not break down at the same rate in every field.
The biodegradation process depends on several factors:
- soil temperature
- soil moisture
- microbial activity
- film thickness
- material formulation
- local climate
- time after soil incorporation
- how well the film is mixed into the soil
Warm, moist soil usually supports more microbial activity than cold or dry soil, so biodegradation may happen faster under these conditions.
Film thickness also matters. A thicker film may provide more strength during use, but it may take longer to break down after the crop cycle.
Material formulation affects both working strength and biodegradation. The film must remain functional during use without staying intact much longer than intended.
A film becoming brittle or breaking into visible pieces is not the same as complete biodegradation. Visual changes alone cannot prove that the material has fully broken down.
Recognized agricultural film standards therefore include specific biodegradation tests. They also assess material composition and possible effects on soil organisms to evaluate the product’s wider environmental safety.
PE Mulch Film vs. Soil-Biodegradable Mulch Film
| Point | Conventional PE Mulch Film | Soil-Biodegradable Mulch Film |
| After use | Usually removed from the field | May be incorporated into the soil as directed |
| Main waste risk | Persistent plastic residue if not fully collected | Slow or incomplete biodegradation under unsuitable conditions |
| Recycling | Possible when the film is collected cleanly, but difficult when heavily contaminated | Not designed for conventional plastic recycling |
| Main buyer check | Strength, removal method, and collection plan | Soil-biodegradation standard, required working life, and local soil conditions |
| Upfront cost | Often lower | Often higher |
The better option depends on how the film will be used and managed after harvest. PE may remain practical where clean collection is possible, while soil-biodegradable mulch can be more suitable where thin film is difficult to recover without leaving residue.
What Standards and Tests Should Buyers Check?
A general biodegradable claim does not prove that a film is suitable for agricultural soil.
EN 17033 sets requirements and test methods for biodegradable thermoplastic mulch films used in agriculture and horticulture. It covers soil biodegradation, product performance, material composition, and possible environmental effects.
ISO 23517:2021 applies to biodegradable materials used to produce mulch films and to finished biodegradable mulch films. It includes requirements related to biodegradation, material constituents, and possible effects on terrestrial organisms.
Before ordering, buyers should check:
- whether the standard applies specifically to soil-biodegradable mulch film
- whether the test covers the finished film rather than only the raw resin
- whether the tested thickness matches the product being ordered
- whether the film can remain functional throughout the crop cycle
- whether it suits the local soil, climate, and laying equipment
- whether samples have been tested under realistic field conditions
Laboratory results are important, but they do not replace field testing. A film that meets a standard may still perform differently under a specific crop, soil, climate, or farming method.
If I were comparing two products, I would first test whether each film performs reliably during the full crop cycle. Only then would I compare its end-of-life benefits and supporting claims.
Naturepoly can provide product specifications, samples, and available test documents to help buyers review film thickness, crop-cycle requirements, and local growing conditions before placing an order.
What Are the Limits of Biodegradable Agricultural Films?
Biodegradable mulch film is not suitable for every field or project.
Its upfront price may be higher than conventional PE film, which can limit adoption in cost-sensitive farming systems.
Breakdown also varies by location. Cold, dry, or less biologically active soil may slow biodegradation and leave visible fragments for longer than expected.
These fragments should not be judged by appearance alone. Proper test documents and field monitoring are needed to confirm whether the material is breaking down as intended.
Long-term performance also requires further study across different soils, climates, crops, and farming systems.
Most importantly, a biodegradable label does not prove that a film meets an agricultural soil standard. Buyers should check the finished product, relevant test reports, and intended field conditions before use.
Biodegradable mulch film can reduce persistent plastic residue, but only when the product is properly tested and matched to the application.
FAQ
Are biodegradable agricultural films the same as compostable films?
No. Soil-biodegradable films are tested for biodegradation under soil conditions, while compostable films may require industrial or home composting systems.
Can biodegradable mulch film be left in the field?
It should be handled according to the manufacturer’s instructions. Many soil-biodegradable mulch films are designed to be incorporated into the soil after the crop cycle rather than left on the surface.
Does biodegradable mulch film leave microplastics?
Certified soil-biodegradable films are designed to biodegrade rather than remain as persistent PE plastic. However, visible fragments may appear during the breakdown process, and product quality, soil conditions, and field management can affect the final result.
Conclusion: The Right Film for the Right Field
Biodegradable agricultural films can reduce persistent PE mulch residue in short-term farming applications where used film is difficult to collect.
They are not suitable for every agricultural plastic.
Performance depends on the crop cycle, film thickness, soil, climate, product standard, and field conditions.
The best results come from matching the film to the field rather than relying on a biodegradable label alone.