Storing silage on saline-sodic clay soils in the Riverina presents challenges that extend beyond keeping rain and dust away from the stack. Heavy clay surfaces along the Murrumbidgee irrigation corridor can create difficult conditions for bunker and pit construction, while poor sealing can allow oxygen exchange, reducing fermentation quality. High-performance silage plastic using EVOH co-extrusion provides a technical solution by creating a highly effective gas barrier around stored forage. For corn and lucerne silage, this helps maintain the anaerobic environment needed for stable fermentation and limit losses from oxygen exposure.
Why Gas Barrier Performance Matters in Silage
Successful silage fermentation depends on restricting oxygen after packing the forage. Once oxygen enters through a damaged cover, a poor seal, or a permeable film, aerobic microorganisms can become active and consume valuable organic matter.
This is particularly important for lucerne and corn silage, where preserving fermentable material and maintaining nutritional value are key storage objectives. A high-performance silage plastic can reduce gas transfer compared with conventional polyethylene films, supporting a more consistent sealed environment.
Understanding EVOH Co-Extrusion
EVOH, or ethylene vinyl alcohol, is widely used as a barrier polymer because of its very low permeability to oxygen and other gases under suitable conditions. In agricultural films, EVOH can be incorporated into multilayer structures rather than used as a standalone film.
Seven-layer and nine-layer co-extruded films can combine different polymer layers to provide barrier performance, mechanical strength, flexibility and protection for the EVOH layer. Exact performance depends on the formulation, thickness, processing, and finished-film construction.
A zero-permeability high-performance silage plastic should therefore be understood as a product designed for extremely low gas transmission, rather than literally assuming that no gas can ever pass through the material.
Protecting Fermentation on Riverina Clays
Saline-sodic soils can create a harsh working environment for agricultural operations. Clay surfaces may be hard, uneven and prone to cracking or structural changes depending on moisture conditions. These factors make careful preparation and protection of a silage storage area especially important.
The plastic itself is only one part of the sealing system. Operators should also consider:
● Removing sharp stones and debris before covering the silage.
● Using suitable underlay protection where the base presents puncture risks.
● Achieving a close seal around bunker edges and joins.
● Inspecting the cover regularly for tears, holes or lifted sections.
● Repairing damage promptly with compatible repair materials.
● Using adequate weighting to maintain contact with the forage surface.
A high-performance silage plastic with a strong gas barrier can complement these practices by limiting oxygen transmission through the film itself.
Retaining Organic Acids During Fermentation
During fermentation, lactic acid and other organic acids help preserve silage. The goal is not simply to produce acids but to maintain conditions that support stable fermentation and prevent unwanted aerobic activity.
A highly effective barrier film helps maintain the sealed environment this process requires. For Riverina producers storing corn or lucerne, this can be especially useful where silage must remain protected through extended storage periods and variable seasonal conditions.
7-Layer vs 9-Layer Film Construction
Layer count alone does not determine film performance. A nine-layer product is not automatically superior to every seven-layer product. What matters is the overall construction, including the EVOH barrier layer, polymer selection, thickness, mechanical properties and manufacturing quality.
When comparing products, ask suppliers for technical data covering oxygen transmission, film thickness, tensile strength, puncture resistance and recommended installation practices.
Choosing High-Performance Silage Plastic
For farms along the Murrumbidgee irrigation corridor, base film selection on the complete storage system rather than the marketing description on the roll. High-performance silage plastic with EVOH barrier technology can provide an extra layer of protection when oxygen control is a priority.
For best results, combine an appropriate barrier film with good compaction, clean surfaces, reliable edge sealing and regular inspection.
Conclusion
EVOH co-extrusion offers a technically advanced approach to controlling gas exchange in silage storage. For corn and lucerne stored on saline-sodic clay soils across the Riverina, a high-performance silage plastic can provide the airtight conditions required for effective preservation.
Speak with an agricultural film supplier about EVOH multilayer options and request technical specifications before selecting a film for your next silage project.
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Frequently Asked Questions
1. What is EVOH in silage plastic?
EVOH is a barrier polymer used in multilayer films to provide very low gas permeability, particularly against oxygen.
2. What does zero permeability high-performance silage plastic mean?
It generally refers to film engineered for extremely low gas transmission. You should not automatically assume any flexible polymer film has literally zero gas transmission.
3. Is nine-layer film better than seven-layer film?
Not necessarily. Performance depends on the materials, barrier construction, thickness, and manufacturing quality, not layer count alone.
4. Why is oxygen control important for silage?
Limiting oxygen helps maintain anaerobic fermentation and reduces the risk of aerobic spoilage after the forage has been sealed.
5. Can EVOH film be used for lucerne and corn silage?
EVOH multilayer films can suit different silage crops, provided the product is specifically manufactured and recommended for the intended storage application.