Not sure what size Grain Bunker Size you need for your desired capacity? Try our Grain Bunker Calculator.
Not sure what size Grain Bunker Size you need for your desired capacity? Try our Grain Bunker Calculator.
Got a bumper harvest and need to store grain on-site? Choosing between a grain bunker, silo, grain bags or a shed is one of the most common questions growers ask us. Each method has clear trade-offs and the best option depends on your goals. This guide breaks down where each one wins, then helps you match the right one to your situation.
For a closer look at cost-per-tonne over time, read our piece on evaluating the cost efficiency of different grain storage options.
|
Storage option |
Typical capacity |
Upfront cost |
Best storage duration |
Mobility |
Pest/weather risk |
Labour to load/unload |
Best for |
|
Grain bags |
~200–250 T per bag |
Low |
Short (3–6 months) |
High (place anywhere) |
Higher (needs monitoring) |
Moderate (specialised gear) |
Quick backup storage at peak harvest |
|
Grain bunkers |
~1,000 T –50,000 T on-farm |
Low–medium |
Medium–long (with sealed tarps) |
Medium (set up on a prepared pad) |
Moderate (managed with hygiene + tarps) |
Higher (tarps need 1–3 people) |
Large volumes & bumper-season overflow |
|
Grain silos |
~100T-15,000T |
High |
Long (years) |
Low (fixed) |
Lowest (sealed, aerated) |
Lowest (mechanised) |
Permanent long-term storage of premium grain |
|
Grain sheds |
Large (varies by shed size) |
High |
Long |
Low (fixed) |
Moderate (hygiene-dependent) |
Moderate |
A multipurpose asset that adds property value |
Capacities are indicative for Australian on-farm use and vary by supplier and setup. Use the Polytex Grain Bunker Calculator to size a bunker for your exact tonnage.
Grain bunkers are a tarped, on-ground storage system widely used by Australian growers and bulk handlers to store large volumes affordably.
Advantages
Disadvantages
Growers often use bunkers as a risk-management tool against unpredictable weather and markets. A grain bunker is likely your best choice when you want to:
Helpful tools: the Polytex Grain Bunker Construction Guide and construction & operation video walk you through building and sealing a bunker correctly.
Grain bags (silo bags) are long sealed plastic tubes filled directly in the paddock, a fast, low-cost way to create temporary storage.
Advantages
Disadvantages
Grain bags are ideal as quick backup storage during peak harvest when space is urgent, or when you only need to store grain briefly (around three months). With good prep, sampling and regular checks, they work well. Because of the higher quality risk, avoid relying on bags for more than 3–6 months. Northern Victoria grower Jack Gall made exactly this move, shifting from bags to bunkers as his operation scaled past 20,000 T. Read how Gall Farming made the switch →
Silos are sealed, often aerated steel structures. They are the go-to for growers who want a permanent, controlled environment for premium grain.
Advantages
Disadvantages
If you want permanent, long-term storage for roughly 500–2,000 tonnes of grain, especially premium grain where quality matters, silos are usually your best bet. If you need more than 3,000 tonnes without major capital investment, a bunker is generally the more effective option.
A grain shed is a permanent building that stores grain in bulk and doubles as general farm infrastructure.
Advantages
Disadvantages
A grain shed suits you if you want safe grain storage while also building a multipurpose asset that adds long-term value to your property.
Work through these three questions:
There’s no single best method; the right grain storage solution depends on your tonnage, timeframe and goals. For most Australian growers dealing with variable harvests and large volumes, a bunker offers the best combination of flexibility and cost-efficiency. Many farms run a mix: bunkers for bulk and overflow, silos for premium long-term grain, and bags as harvest-time backup.
Whether you’re a small grower starting out or an experienced bulk handler, Polytex can help you find the right grain storage solution. Not sure what size bunker you need? Try our Grain Bunker Calculator, explore our grain protection range or contact the team on 1300 059 003 for expert advice.
I have a bumper harvest and need to store some grain on-site. What is the best grain storage method to use – grain bunker, silo, grain bags or shed? This is a common question that growers face and regularly discuss with us. Each method has its advantages and disadvantages, and your most effective option depends on your overall goals. Here we outline the different grain storage options available and offer guidance on which one is best suited for specific purposes.
Advantages of Grain Bunkers
Affordable and cost-effective. Grain Bunkers are a very cost-effective method for storing large amounts of grain.
Flexible and adaptable. Grain bunkers can be set up on-farm with good drainage and access and can easily be expanded.
Large Capacity. Grain bunkers offer much greater capacity compared to silos or grain bags. Silos have an average size of 500-700T, and grain bags average approx 250T each whereas grain bunkers average 2000T for on-farm use and 20,000 – 30,000T each for grain handlers. They can easily be expanded to accommodate excess grain if needed.
Disadvantages of Grain Bunkers
Pests and rodents: Insects, rodents, and birds can more easily access grain stored in bunkers compared to enclosed storage structures like silos. However this risk can be mitigated through good site hygiene and well-sealed tarps on your bunker.
Suitable Pad Requirements: A large space is required for a grain bunker pad with all-weather truck access and good drainage.
Labour requirements: Handling large tarps when in-loading or out-loading normally requires 3 or more personnel, however with some creativity this is possible with just 1-2 personnel.
Bunkers are often used as a risk-management strategy by growers to minimise the impact of adverse weather events and variable market conditions.
Grain bunkers present many opportunities to manage your grain storage better. Below are some common scenarios when grain bunkers would be your best option.
Feed grain crop. Cost-effective storage for feed-grade grain to be used on-farm.
Capacity to hold excess stocks produced in bumper seasons allowing you to transfer grain to bulk handlers post-harvest.
Marketing opportunities. Storing grain on-farm gives the farmer marketing flexibility to time the sale of his grain for optimum return on their yield.
Grain bunkers can eliminate logistic and transport lead times during bumper harvests.
Advantages of Grain Bags
Cost-Effective: Grain bags are more cost-effective than building permanent storage structures like silos. This can be especially beneficial for growers with limited budgets or temporary storage needs.
Flexible Storage Quantity and Location: Grain bags offer flexibility in terms of capacity and location. They can accommodate varying quantities of grain, making them suitable as a backup storage option for high-yielding harvests. They can also be a handy option for collecting grain direct from the chaser bin and storing it at a central site on the farm.
Quick Setup: Setting up grain bags is relatively quick compared to constructing traditional storage facilities. This can be especially advantageous during peak harvest times when the need for storage space is urgent.
Disadvantages of Grain Bags
Risk of Damage: Grain bags are susceptible to damage from rodents, birds, pests, and even machinery during loading and unloading. Proper sealing, handling and good site hygiene are essential to prevent these issues.
Limited Long-Term Storage: While grain bags are suitable for up to 3-6 months storage, they are not the best option for long-term storage due to grain quality risks and potential degradation of the bag material over time.
Labour and Equipment: Loading and unloading grain bags require specific equipment and labour. Improper loading techniques can lead to uneven settling and air pockets within the grain.
Truck Access When Outloading: While leaving grain bags at various locations around the farm is handy when harvesting, it can present problems when outloading. If the ground is wet, truck access to bags may not be feasible leaving grain inaccessible.
Moisture Management: While grain bags are designed to be airtight, proper moisture management is essential to prevent mold, fungal growth, and spoilage within the bags. Sampling and regular checks are necessary.
Quality Control Challenges: Monitoring and maintaining grain quality within bags can be more challenging compared to traditional storage facilities that offer better ventilation and control.
Grain bags are ideal for a quick backup storage solution during peak harvest times when the need for storage space is urgent. They are also a good option if you are only planning a very short storage time (e.g. 3 months). With good preparation, sampling and regular checks, grain bags can be an effective option.
Due to the higher risk of damage to grain quality compared to other storage options, it is not a good idea to rely on bags for longer term storage (more than 3 – 6 months)
Grain silos are a popular method of storing grain on-farm. Here are the key reasons why.
Advantages of Grain Silos
Effective Grain Storage: Silos provide a controlled environment for grain storage, protecting it from moisture, pests, and other environmental factors that can lead to spoilage. This helps maintain grain quality.
Space Efficiency: Silos can store large amounts of grain in a relatively small footprint, making them suitable for both large and small farms or grain-handling facilities.
Mechanical Aeration: Many silos are equipped with mechanical aeration systems, allowing for precise control of temperature and moisture levels within the stored grain, which helps preserve quality.
Reduced Labour: Loading and unloading grain from silos require less labour than other storage options.
Longevity: Well-maintained silos can have a long lifespan, often 25 years or more.
Improved Inventory Management: Silos enable better inventory tracking and management, facilitating efficient logistics and grain marketing.
Disadvantages of Grain Silos
High Initial Cost: Constructing silos can be expensive, with significant upfront costs for materials and installation.
Low storage capacity. An average silo can store approx. 1000T of grain. This may be fine for some growers but if you are looking to store more than 3,000T other storage options like grain bunkers may prove more effective.
Maintenance Costs: Silos require regular maintenance to ensure they remain structurally sound and to prevent issues such as rust and corrosion.
Limited Mobility: Unlike grain bags, silos are fixed structures, making them unsuitable for temporary storage needs or for farms with changing field locations.
Complexity: Operating and maintaining silos, especially the associated machinery and aeration systems, can be more complex than other storage methods.
Temperature Control: In extremely hot or cold climates, additional insulation and temperature control measures may be required to prevent temperature extremes inside the silo.
If you are a grower looking at a permanent, long-term storage option for 500T – 2000T of grain, then silos are likely your best grain storage option.
If you are looking at more than 3,000T without significant capital investment then other storage options like grain bunkers are likely to be a better option.
Advantages of Grain Sheds
Farm Asset: Sheds will always add value to your property with a long service life.
Multipurpose use: Grain sheds can be used for machinery or other purposes when not storing grain.
Safe and secure: Storing grain in a shed is safer than other grain storage options like silos.
Disadvantages of Grain Sheds
Significant upfront cost: Grain sheds are a high capital investment requiring large initial outlay.
Pests and hygiene: Grain sheds need a high level of hygiene. This is particularly necessary when using the shed for multiple purposes at different times of the year.
Fumigation limitations. Fumigation inside a shed can be tricky when seeking to get a good seal all around the edges required for fumigation to be effective. Polytex can supply fumigation tarps for fumigating inside a shed and can provide tips on best practices.
If you are looking for a safe grain storage solution while also increasing your farm assets then a grain shed may be your best option.
So there it is, the key advantages and disadvantages of the four main grain storage options available to Australian growers and grain handlers. As you can see, your best grain storage method depends on your current circumstances and what your ultimate goal is when storing grain.
For more information and expert advice on grain storage solutions contact the team at Polytex on 1300 059 003. Whether you are a small grower starting out or an experienced large-scale grain handler, Polytex is here to assist with your grain storage requirements and help you find the best solution.