Prevent Combine Fires During Sunflower Harvest

In 2024, North Dakota is expected to harvest an estimated 320,000 acres of oil sunflowers and an estimated 72,000 acres of confectionary sunflowers, according to the National Agricultural Statistics Service (NASS). Crop harvest progress reporting through NASS indicated that sunflower harvest was 28% complete in North Dakota on Oct. 21, which is ahead of last year’s 19% harvest completion progress. Warm and dry weather conditions have allowed harvest to progress quickly, with limited precipitation-related delays. However, warm, dry and windy conditions increase the risk for combine fires, warns Angie Johnson, North Dakota State University Extension farm and ranch safety coordinator.

“Mix warm, dry harvest conditions with a high wind speed, and you have a recipe for harvest fires, especially when combining sunflowers,” Johnson says.

According to Daryl Ritchison, North Dakota Agricultural Weather Network (NDAWN) director and NDSU state climatologist, autumn in North Dakota is one of the windiest seasons. Ritchison encourages producers to utilize NDAWN data to help make safe harvest decisions. Producers can monitor current wind speeds, temperatures and humidity values that are updated live every five minutes at https://ndawn.info/.

“The high wind speeds we are experiencing and the large amount of extremely dry plant material in our fields and grasslands creates perfect conditions for fire when provided with an ignition source, such as the hot exhaust from the combine’s turbocharger or exhaust manifold, or even from an electrical malfunction in a plastic wiring harness on the combine,” Johnson says.

Combine fires can occur at any time with the right conditions. Sunflowers, however, pose a greater risk because of the large volume of dust and particulate they produce while being harvested, says Johnson. Research from South Dakota State University shows that the white portion inside the stalk, known as the pith, breaks down into very small, tiny particulate pieces with large surface areas that easily get sucked into the fan that is pulling air through the machine’s radiator to cool down the engine. That pith dust and particulate easily stick to engine and exhaust components and can ignite when coming in contact with the turbocharger and exhaust system of the combine.

“Believe it or not, there was a time when producers quit raising sunflowers because of the fire risk and loss of combines due to fires,” Johnson says. “Fortunately, we have improved prevention tools and strategies to help mitigate and reduce the risk of combine fires during sunflower harvest.”

Johnson shares the following tips for reducing the risk of combine fires while harvesting sunflowers:

• Pre-operational checks. Take time to walk around the combine before the start of each day during harvest season. Use an air compressor or leaf blower every day when the machine is off and cooled down to remove dirt, dust, chaff and other plant reside that has accumulated. Always wear hearing protection, eye protection and respiratory protection such as an N95 mask when using an air compressor or leaf blower to remove plant dust and reside. While blowing off residue, look in high-risk areas, such as the engine and engine compartments, exhaust systems, and fluid systems, such as hydraulic pumps, pump drives, and fuel lines. In addition, monitor electrical systems, such as fuse boxes, as well as gearboxes, batteries and cables. When cleaning, take time to look for any issues that require repair, such as leaking hydraulic hoses that can cause chaff to stick and build up, creating an easy fuel source for a fire.
• Take time to service the machine daily based on the combine’s operator manual. Grease and lubricate bearings and chains and continue to look for areas that have excessive wear or damage.
• Watch for wiring issues. Today’s combines are controlled by many sensors and electrical components that are extremely complex. Take time to glance through wiring systems to see where wires appear to be unrestrained or if wires appear to be damaged from rubbing or making contact with moving parts.
• Monitor gauges and warning signs. If you begin to notice increased fuel consumption, loss of hydraulic pressure, fuses that continue to fail or blow out regularly, or increased temperature gauges on your machine, take the time to stop and determine the cause, as these warning signs indicate a malfunction of the machine.
• Use an infrared thermometer. Warm up your combine before taking it to the field and use an infrared thermometer to determine the operating temperature of your combine’s bearings. Safely open the combine’s shields, and from a safe distance, point the infrared thermometer at a bearing to read the measured temperature. If a bearing is at a higher temperature than the others, it is time to replace that bearing, as it may be worn or damaged. Infrared thermometers are inexpensive (less than $50) and can be found at many hardware and farm stores. Hot bearings are a combustion source.
• Install an air intake kit. An air intake kit allows clean air found above the combine’s “dust cloud” to enter the combine’s air intake screen, instead of taking in the dusty, dirt-filled air produced from harvesting the crop. Take the time to consider an option that will work best for you and your combine.
• Avoid combining during fire danger conditions. Relative humidity values are low in the fall, increasing the risk of fire, especially in the late afternoon hours. Keep an eye on the air temperature and wind speeds. Shutting down when conditions are hot, dry and windy could prevent you from losing your combine to a fire. Be aware and find out if your area is in a fire danger zone by visiting: https://ndresponse.gov/burn-ban-restrictions-fire-danger-maps.
• Shutting down for the night. Always allow combines to cool down before parking them inside a shed for the night. Also allow the combine to cool down before refueling the machine. Make it a safety practice to shut the combine off before refueling.
• Carry two, fully charged fire extinguishers. Ideally, you should have two 20-pound, charged fire extinguishers on your combine. Have them ready and operational and review with workers how to use them when needed. Call 911 immediately to get your closest fire department on scene.
• Create a soil perimeter. If you choose to harvest during high wind and temperature conditions, make a tillage pass around the perimeter of the field to prevent the possibility of a fire spreading to other areas on the landscape should a combine fire occur. If possible, consider having a water truck nearby.

“Good machine maintenance, cleaning and monitoring can help reduce the incidence of combine fires during crop harvest,” says Johnson. “Make farm safety a priority on your farm this fall. Combines and crops are replaceable – you are not.”