Challenging weather conditions in the Northeast and Midwest have made it difficult to put up dry hay.
“Wet soils, humid conditions and frequent rains have not been conducive to adequately drying hay,” says Casey Guindon, a field and forage crop specialist with Pennsylvania State University.
“While it may be tempting to store hay slightly on the wet side to protect some yield and quality, there are many dangers in storing hay above 20% moisture,” she says.
As temperatures rise, the danger of spontaneous combustion increase. Smoldering hay gives off a strong, pungent odor, and is an indication a fire is occurring.
If even the slightest smell is present, take temperatures of the stack, says Marvin Hall, a forage management specialist also with Penn State. Hay temps and related actions:
- Temperature 125 degrees F -- No action needed.
- Temperature 150 degrees F -- Entering the danger zone. Temperatures should be checked twice daily. If possible, stacked hay should be disassembled to allow more air to move around heated bales for cooling.
- Temperature 160 degrees F -- Reaching the danger zone. Temperature should be checked every two hours. If possible, stacked hay should be disassembled to allow more air to move around heated bales for cooling.
- Temperature 175 degrees F -- Hot spots or fire pockets are likely. If possible, stop all air movement around hay. Alert fire service of a possible hay fire incident.
- Temperature 190 degrees F -- Remove hot hay. This should be done with the assistance of the fire service. The fire service should be prepared for hay to burst into flames as it contacts fresh air.
“Use caution when moving heated bales because they can burst into flams when exposed to fresh air,” advises Hall. “Wetting hot bales before moving them can help control the hazard.