Baling is the process of compacting cut crop material into a compressed, bound bale. The crop is cut and raked beforehand, then gathered and compressed into a form that can be handled, stacked, stored, and transported far more easily than loose material. Silage, hay, straw, salt marsh hay, flax, and cotton are all commonly baled, and the list does not end there.
Once formed, bales may be bound with twine, netting, wire, or strapping, and different balers produce different shapes, most commonly cylindrical (round) and rectangular. The choice of bale type, binding, and wrapping determines how well the crop holds its value in storage, which is really the whole point of the exercise.
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One Thing Baling Does Not Do
It is worth clearing up a common misconception straight away, because it causes real losses.
Baling does not dry a crop. For hay, the crop must already be dry before it goes into the baler, typically down to 14 to 18% moisture. Baling hay that is still damp traps moisture inside a dense bale where it cannot escape, and the result is mold, nutrient loss, and in serious cases spontaneous combustion. Hay fires in barns are not rare, and they usually trace back to bales made too wet.
What baling does is preserve the condition the crop was already in, and protect it from the elements thereafter. Get the crop right first, then bale it.
Dry Baling and Wet Baling Are Different Processes
There are two fundamentally different reasons to bale, and confusing them is where most feed losses begin.
| Dry Baling (Hay, Straw) | Wet Baling (Silage, Haylage) | |
|---|---|---|
| Moisture at baling | 14 to 18% | 50 to 70% |
| Preservation method | Dryness prevents spoilage | Anaerobic fermentation preserves the crop |
| Binding | Net wrap or twine holds bale shape | Net wrap first, then airtight film to seal |
| Air | Airflow is fine, even helpful | Air must be excluded completely |
| Failure mode | Mold and heating if baled too wet | Spoilage if the seal is breached |
Net wrap alone will never make silage, because it is an open mesh that lets air through freely. Silage bales need net wrap to hold their shape and then several layers of airtight film to create the oxygen-free environment fermentation requires.
“The question we field most often is whether net wrap alone is enough for a silage bale. It is not, and the confusion is understandable because both products come off a roll and go on the same machine. Net wrap is structure. Film is the seal. On a dry hay bale you only need the first. On a silage bale you need both, and skimping on the film layers is where a season’s forage quietly disappears.”
— Sue Su, Marketing Director of Silopak
A Short History of Baling
Before the 19th century, hay was cut by hand with scythes and gathered with forks into haystacks. The size of the stack mattered a great deal. Too large, and the interior heated to the point where spontaneous combustion became a genuine risk. Too small, and the pile was too exposed, holding moisture and rotting. A well-built stack lifted the plant fibers off the ground so air could circulate and water could drain, letting the grass cure evenly and hold its feed value into winter.
Mechanical cutting devices arrived in the 1860s, and from them came mechanical mowers and the first balers. In 1872, Charles Withington invented a reaper with a knotter mechanism capable of bundling and binding hay. Cyrus McCormick commercialized the design in 1874.
The automatic baler arrived in 1936, when a Davenport, Iowa man named Innes built a machine that tied bales with twine using Appleby-type knotters taken from a John Deere grain binder. The idea was sound but the machine was unreliable in the field. Pennsylvania farmer Edwin Nolt, having bought one and found it did not work, built his own version through the winter of 1936 to 1937, salvaging the bale chamber from the Innes machine. He filed a patent in 1938, and his design became the first commercially successful automatic pick-up, self-tying baler. New Holland eventually acquired it.
The round baler has older roots than many assume. An early version was shown in Paris by Pilter in the late 19th century, a portable machine designed to work alongside threshing machines. The large round balers familiar on farms today, however, are a much later development, arriving with hydraulic technology in the second half of the 20th century.
Round Bales and Square Bales
Which shape a farm chooses depends on the crop, the machinery available, and how the bales will be stored and handled.
Round bales shed water naturally because of their curved surface, which makes them better suited to outdoor storage. They are also well suited to wrapping, and they are the standard for round bale silage. The drawback is that they do not stack efficiently, so they consume more space where storage is tight.
Square and rectangular bales stack tightly and use storage space far more efficiently, which matters for indoor storage and for transport, where density per load determines cost. Large rectangular balers can produce very dense bales with adjustable size and weight, making them the choice where bales travel long distances to a mill or a buyer.
Not every crop suits every shape, and the decision usually comes down to what the farm already owns and what the storage situation demands.
Choosing the Right Baling Supplies
The machine and the consumable are two separate purchases from two different specialisms.
For the baler itself, our group company Jummos manufactures balers and baler wrappers. Silopak manufactures the wrapping materials that go with them: silage film, bale net wrap, round bale film, and baler twine. Wrapping is what protects the finished bale from rain, UV, and rodents, and in the case of silage, it is what makes the fermentation possible at all.
We have manufactured agricultural film and net wrap since 2011 from premium virgin resin, supplying farms across Australia, New Zealand, North America, Europe, and Asia.
Frequently Asked Questions about Baling
Q: Does baling dry the crop?
No. This is a common and costly misunderstanding. Hay must already be dry, typically 14 to 18% moisture, before it goes into the baler. Baling damp hay seals moisture inside a dense bale where it cannot escape, causing mold, nutrient loss, and heating that in serious cases leads to spontaneous combustion. Barn fires from wet-baled hay are a real and recurring problem. Dry the crop in the field first, then bale it.
Q: Can I make silage with net wrap alone?
No. Net wrap is an open mesh designed to hold a bale in shape. It allows air through freely, so it cannot create the oxygen-free environment that silage fermentation requires. For silage bales, net wrap goes on first to compact and hold the bale, then several layers of airtight LLDPE film are applied over it to seal out oxygen. Both products are needed, and each does a different job.
Q: Are round bales or square bales better?
Neither is universally better. Round bales shed water because of their curved surface, making them well suited to outdoor storage and to wrapping for silage, but they stack inefficiently and consume more storage space. Square and rectangular bales stack tightly, using storage and transport space far more efficiently, which lowers haulage cost per tonne. The right choice depends on your crop, your machinery, your storage, and whether the bales stay on farm or travel.
Q: Does Silopak sell balers?
No. Silopak manufactures the wrapping consumables: silage film, bale net wrap, round bale film, and baler twine. The baler machinery is produced by our group company Jummos, which makes balers and baler wrappers. This means a buyer can source the machine and the wrapping materials from the same manufacturing group, but they are two distinct product lines from two separate brands.
Reviewed by Sue Su, Marketing Director of Silopak, on 5 August 2026. The section on baling moisture has been added to address a widespread misconception that causes avoidable feed and barn losses.
