How to Reduce Your Combine Fire Risk

Editor's Note: This story includes some archived DTN coverage.

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OMAHA (DTN) -- Expanded drought and lack of rain late this summer has sparked more concerns about potential combine fires as farmers enter harvest.

Some farmers have been posting on social media that they are anxious about possible combine fire dangers. News media and crop progress reports from the United States and Canada have already noted some combine fires this year.

On Aug. 13, a combine fire near Great Falls, Montana, led to a fast-moving fire that burned about 45 acres (https://www.krtv.com/…).

The Sedalia, Kentucky, fire department reported a fire on Sept. 6: "Combine fire this morning. We received a call at 5:32 am of a combine on fire. On arrival the combine was fully engulfed and field was starting to burn. The owner stated the combine was last used yesterday afternoon. We are sorry for (their) loss during this harvest season." With two fire departments and eight firefighters responding, they put the fire out. "Thankful it didn't spread any worse due to the prolonged dry conditions the area has faced," said the department on social media with pictures. (https://www.facebook.com/…)

MORE COMBINES IN FIELDS

The danger of fires is increasing as more combines start to enter the fields. The first corn harvest update from the weekly USDA NASS Crop Progress report (https://www.dtnpf.com/…) estimated that 4% of corn has been harvested nationally, behind 2024's 5% and 1 point ahead of the five-year average of 3% at this time. Spring wheat harvest is 85% complete as of Sept. 7, ahead of last year's pace of 83% and the five-year average of 85%.

While farmers often talk about dry fields leading to potential fire started by equipment, there are several reasons farmers need to be extra careful at harvest time.

"Precipitation is just one part of the picture though when we talk about fire risks. Dry air or low relative humidity, warm temperatures, and windy conditions can also enhance fire risks," said DTN Meteorologist Teresa Wells.

EASTERN CORN BELT NEEDS TO WATCH

"For those areas in the Eastern Corn Belt that have been plagued by drier conditions at the end of the growing season, they will need to watch for days that could have relative humidity below 30% and sustained winds stronger than 10-15 miles per hour. The National Weather Service is also a good resource for monitoring days that have higher fire risks because they will issue Fire Weather Watches or Red Flag Warnings that alert the public that critical fire weather conditions are expected to occur or are occurring," Wells said.

Eastern Corn Belt farmers have noted drought has expanded in the last few weeks -- increasing their concerns. They are right to be more cautious in the fields.

"Looking across the Corn Belt, the Eastern Corn Belt is most prone to fires this harvest season as we've seen drought expanding since mid-August," said Wells.

"From Aug. 19 to Sept. 2, there has been roughly a 15% increase in the amount of land across the Midwest that has been placed under abnormally dry (D0) to exceptional drought (D4) levels. Most of the drought has expanded across Missouri, Kentucky, southern Illinois, Indiana, and Ohio."

The most recent U.S. Drought Monitor shows the expansion. (See https://droughtmonitor.unl.edu/…)

Other areas have seen more rain.

"Over the past 30-60 days, the Western Corn Belt has seen a more active pattern with some areas seeing above-average precipitation. Portions of South Dakota, southern Minnesota, northern Iowa, and southern Wisconsin have seen rainfall reach 1-2 inches above average during a 30-day period ending on Sept. 7," Wells said.

HARVEST WEATHER OUTLOOK

As for the harvest weather outlook, "For the rest of September, precipitation is favored to be below average across the eastern, southern and central Corn Belt while the Northern Plains could see above-average precipitation. October shows near-average precipitation centered across the Great Lakes while drier conditions could potentially expand across the Northern Plains," she said.

As for the Canadian harvest situation and how prone it is to equipment and field fires, Wells said while the heart of the Canadian Prairies has little to no drought, D0 to extreme drought (D3) mainly covers the fringes of the Canadian Prairies.

"Southwest Saskatchewan has severe drought (D2) with D3 pockets extending into western Manitoba. Upper-air ridging has been dominant across much of the Canadian Prairies since early August and this has kept precipitation limited.

"Parts of the southern and eastern Prairies could be the most prone to fires this fall with drought already in place. However, if we can get the upper-air ridge to break down and shift east from time to time, then a few troughs could move through and provide increased chances for precipitation. Long range model guidance hints at the ridge breaking down around mid-September as a trough from the Gulf of Alaska pushes east into the Prairies," Wells said.

DANGER OF EQUIPMENT FIRES

Even if a wildfire is contained to just machinery and doesn't spread into a field -- or worse yet, a small town like in Missouri in 2022 (https://www.dtnpf.com/…) -- these fires can endanger lives, as well as cost a lot of money and valuable time for farmers.

"Equipment fires, specifically combine fires, are a serious threat during the harvest season," North Dakota State University Extension Farm and Ranch Safety Coordinator Angie Johnson stressed in a news release in 2024. "No one wants to lose their combine or the remaining unharvested crop in the field due to fire. The biggest risk, however, is the loss of human life, as combines, crops and other equipment can be replaced -- you cannot."

South Dakota State University Extension noted in one of its past news releases, "Many steel combine components have been replaced with combustible components; combines are larger and process more biomass; chain and belt drives have been converted to hydrostatic systems, which increase the risk of oil leaks and combustible hoses that can sustain a fire; (and) the wide-scale use of powered sensors and controls systems which may provide the spark to ignite dust and chaff." (See https://extension.sdstate.edu/….)

SDSU stressed if there are dry conditions and wind speeds close to 30 miles per hour and higher, fires are inevitable. Producers are encouraged to delay harvest until evening when winds decrease or else wait for precipitation. "Park the combine during periods of high risk," SDSU stated. "Remember your safety comes first."

The National Corn Growers Association has also given tips in the past on safety procedures to reduce the risk of combine or machinery fires. (See https://www.dtnpf.com/….)

This included encouraging farmers to recognize and be careful around combustible material, such as leaves, stalks, husks, dust, oil and fuel that come into constant contact with potential sources of ignition from farm equipment exhaust, bearings and electrical wiring.

Here are some of the tips to reduce fire risk:

-- Farm equipment fires can still occur despite the most vigilant care. It is important to have a working, fully charged fire extinguisher in each machine as well as in your vehicle (A-B-C, 5- or 10-pound).

Iowa State University Extension recommended having a smaller 10-pound extinguisher in the cab and a larger 20-pound one at ground level attached to equipment. ISU added it can also be beneficial to keep a pressurized water extinguisher (class A) on equipment, since they can help extinguish fires but also cool hot surfaces and serve as a water source to clean hands or rinse off after a fuel or chemical spill.

-- Keep farm equipment clean, such as with a pressure washer, and particularly the engine compartment since most machinery fires start there. ISU added that using a leaf blower or compressed air can keep machinery clean in the field and suggested doing it at night because in the morning, the dew or overnight rain can make dirt and residue harder to remove. However, some farmers on social media have questioned if battery leaf blowers are safe to use, since they can build up electricity and can shock the user.

-- Check engine fluid levels at the start of the day, particularly coolant and oil levels in all equipment that will be used. Look for any possible leaking fuel or oil hoses, fittings, or metal lines. Should a leak be found, repair it right away.

-- Check the exhaust system, as surfaces containing flammable material can ignite fires.

-- An arcing electrical wire can generate extremely high temperatures in farm machinery. Replace any worn or malfunctioning components.

-- Worn bearings can reach high temperatures, which can cause any rubber belt coming in contact with this intense heat to ignite. Look for worn bearings, belts, and chains frequently and replace.

MORE TIPS FROM ISU

ISU, in past blogs written by its field agronomists Joshua Michel and Terry Basol, added some of the following tips:

-- Inspect and clean ledges or recessed areas near fuel tanks and lines.

-- Prior to fueling, turn the combine off and wait 15 minutes to reduce the risk of a spill volatilizing and igniting.

-- Invert and shake fire extinguishers once or twice a season to ensure machine vibrations don't compact the powder inside. Class A water extinguishers need to be kept in a heated area during winter or they will freeze.

-- Keep a shovel on the combine to throw dirt if needed.

NDSU RECOMMENDATIONS

NDSU's Johnson recommended people "Take time to walk around the combine before the start of each day during harvest season."

Some of her tips included the following:

-- Pre-operational checks: 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. While blowing off residue, look in high-risk areas, such as the engine and engine compartments, hydraulic pumps and pump drives, gear boxes, batteries and cables. When cleaning, take time to look for any issues that require repair, such as leaking hydraulic hoses that can be a perfect place for 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 damaged from rubbing or making contact with moving parts.

-- Use an infrared thermometer. Hot bearings are a combustion source. 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 one bearing has a temperature much higher than the others, it may be worn or damaged. Plan to replace the bearing as soon as possible. Infrared thermometers are inexpensive (less than $50) and available at many hardware and farm stores. Another great time to check the temperature of the combine's bearings is while you are waiting for the truck or grain cart.

-- 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. Avoid harvesting when it is hot and dry. Relative humidity values are low in the fall, increasing the risk of fire, especially in the late afternoon hours when temperatures rise. Limit the harvesting of soybeans that are extremely dry. Soybean moisture can get as low as 8% to 9% on a warm, dry afternoon. Keep an eye on outdoor air temperature and wind speeds. As hard as it is to shut down for the day when conditions are favorable for harvesting, shutting down when temperatures are hot 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 your state's websites. For example, in North Dakota go to https://ndresponse.gov/….

-- Create a soil perimeter. If you choose to harvest during high wind and temperature conditions, make a tillage pass around the perimeter of your field to prevent the possibility of a fire spreading to other areas.

-- Strategically park harvest equipment. While harvesting a field, park your semis, trucks, pickups, tractors, grain carts, etc. in a place with minimal vegetation. Hot exhaust can be emitted from these vehicles and can start a fire in the ditch if dry grass is present. Before parking equipment and machinery in a shed or quonset for the night, let them cool down first to reduce the risk of a building fire.

"Before going out to combine, let others know your plans and field location," Johnson stressed. "If you do not return when you say you will, have someone check to make sure you are OK. This also means you should carry a fully charged cellphone with you while you are combining," she said.

See NDSU's crop harvest checklist at https://www.ndsu.edu/….

WHAT TO DO IF FIRE BREAKS OUT

ISU and NCGA both emphasized it's most important to escape the machinery and call for help.

-- Should a fire break out while a machine is being operated, shut off the engine, grab the extinguisher and exit the vehicle immediately. Be a safe distance from the vehicle at all times if a fire does occur. Call 911. Attack with fire extinguishers if it is safe to do so. Try to fight from the "black," the area already burned. Attacking a fire from areas with combustibles (e.g. dry corn stalks) is much riskier. Use the flexible hose on the extinguisher to spray the base of any visible flames continuously to cool the fire and prevent a reflash until help arrives.

-- Always stay upwind of a fire to minimize the risk of exposure from smoke, heat, and possible flames (due to wind gusts).

-- Be mindful of non-ag equipment vehicles that may be in the fields. UTVs or passenger vehicles often sit closer to the ground and can be more prone to causing field fires. Residue buildup in UTV engine compartments can start a fire.

-- Newer diesel engines often go through a regeneration process to burn soot from their DPF (diesel particulate filter). During this process, exhaust temperatures can reach extremely high levels, often more than 1,000 degrees Fahrenheit. Keep equipment clean and do not park or work in an area where the exhaust is exiting the vehicle near combustible material. This helps ensure equipment in a regeneration state does not ignite a fire.

Finally, ISU's agronomist team emphasized the importance of a plan:

-- Create lists of the 911 addresses for each of your field locations prior to harvest and have them easily accessible to family and farm employees. Many fire departments have GPS equipment onboard their apparatus to assist in directing them to incidents. When an incident is called in with a 911 address, dispatch can more readily identify the incident location and relay this information to drivers. Precious time can be saved when help can be dispatched immediately with GPS guidance rather than having to doublecheck maps and directions.

(See more tips from ISU at https://crops.extension.iastate.edu/… and the blog https://crops.extension.iastate.edu/….)

When you're finishing combining but then dealing with baling, you can check out some tips on how to prevent baler fires at: https://www.dtnpf.com/….

CREATING A FIREBREAK USING TILLAGE

The following are suggestions ISU made about creating a firebreak using tillage:

-- Making a tillage pass along the outside edge of a field (especially a cornfield that can provide ample fuel for a fire because of high amounts of residue) has been a proven preemptive strategy to help prevent fires from spreading into a field.

-- If safe to do so, making a firebreak with a tillage pass can help stop an active, out-of-control fire from spreading. Create an area that won't fuel the fire, so the fire will burn itself out.

-- A good rule of thumb is to create a firebreak that is two to three times as wide as the nearest surface vegetation or plant residue is in height (example; 3-foot-tall brome grass along a field edge = 6-to-9-foot tillage width). Keep in mind that depending on wind speed and gusts, the radiant heat and embers from a fire can "reach out" sometimes twice as far as they normally would be able to. Consequently, a firebreak may need to be considerably wide (up to 30-plus feet) to help ensure proper fire containment.

DTN Staff Reporter Russ Quinn contributed to this story.

Elaine Shein can be reached at elaine.shein@dtn.com

Follow her on social platform X @elaineshein

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