Prescribed Prairie Burn Tips
If your land is enrolled in a Conservation Reserve Program (CRP) you may already be considering a prescribed prairie burn in order to meet your contract management requirement, whether that be this fall or within the next year.
As you begin to plan, consider the following highlights shared by experts from Pheasants Forever, University of Northern Iowa Tallgrass Prairie Center, Iowa Department of Natural Resources (DNR), and Iowa State University Science-Based Trials of Rowcrops Integrated with Prairie (STRIPS). They are: Greg Schmitt, Iowa DNR; Tim Youngquist, ISU Prairie STRIPS; Justin Meissen, UNI Tallgrass Prairie Center; and Allie Rath, Pheasants Forever.
Reach out to your local conservation organizations for additional resources and support in creating your specific prairie burn plan, and ensure the proper authorities are informed about your plan and timeline.
Environmental Conditions and Timing
Weather is one of the biggest unknowns to factor in and to understand in terms of how certain conditions will affect your plan.
Wind speed, relative humidity, and temperature can change unexpectedly and quickly on your planned burn day. Monitor these conditions by the hour and keep in mind that:
- Fire carries faster with a low relative humidity; 30% and lower is too low to conduct a burn.
- Wind speed could be too low; no wind is a poor day for a burn. Instead, 15 to 20 mph is a good, consistent level.
- Fall burns can be tough if the plants aren’t dry, especially if there has been snow and freezing conditions.
- Utility poles, plastic culverts, fiber optics – you have to be mindful of these along the roads.
- Grassland can generate a lot of smoke, so keep in mind where there are well-traveled roads in order to avoid causing low visibility.
Even a year in advance of your anticipated burn day, do regular mowing of fire breaks to manage the volume of thatch that could catch fire and cause problems later. Consider that:
- May 15 – August 1 is generally nesting time for wildlife, and you should keep out of the prairie in order to preserve their habitat.
- In a fall burn, plants will respond to the fire by producing more seed and blooms, which will result in a better stand in the spring.
For a safe burn, your burn site should incorporate a change in vegetation so the fire won’t spread, called a fire break. This could be a ditch or road or a mowed strip along the prairie. In addition, one pass with tillage equipment can add to the effectiveness of a burn break.
A fire break’s width is determined by the height of vegetation alongside it. The width should be three to four times the height. For example, if you have 6-foot-tall bluegrass, you would need a 24-foot-wide burn break in order to avoid falling, burning vegetation.
If there is still concern about the width, you can mow an additional strip of prairie along the perimeter (a heat reduction area) so that falling plants have ever more space to fall.
Other topics to consider as you create a burn plan and manage the burn during the day:
- Burning into the wind is a safe, controllable approach.
- Slow-moving fire will eat up more fuel because it will have a longer residence time in the vegetation.
- Cotton and leather clothes (especially leather gloves)
- Goggles or sunglasses (heat can scorch your eyebrows)
- Two-way radios
- Backpack steel pump (to create a wet line and manage spot fires)
- Drip torch (filled with one-part diesel, two parts gasoline)
- Leaf blower (moves the fuel)
- Backup water source
- Water and snacks (your fuel)
- Rake, shovel, or other hand tools (to tamp out spot fires)
Take caution and be careful in planning; a boring burn is a better burn.