While most prescribed fires are conducted during the dormant season, researchers and fire managers suggest burns done between July and September can provide benefits for land managers and public safety.
Higher levels of humidity and increased vegetation moisture in the growing season help to moderate fire behavior and reduce the risk of an escaped fire.
Growing season prescribed fires can also be used to manage rangeland woody encroachment, manage certain weed species, and provide wildlife habitat benefits. The benefits and risks along with fuels, wind speeds, humidity and landowner goals are considered when building the prescription for the plan.
The key with growing season prescribed fire, is a good amount of previous year’s vegetation present. If there is none to very little previous year’s vegetation present, the prescribed fire will not be successful, he said.
According to KC Olson, professor of range beef cattle nutrition and management at Kansas State University, prescribed-fire research conducted between 2014 and 2020 documented the effects of growing season prescribed fire compared with dormant season prescribed fire on rangeland health and performance of grazing livestock.
“Results were quite compelling. Prescribed fire applied in either early August or early September strongly suppressed sericea lespedeza over a four-year period. No differences were observed between treatments in native grass composition, forage biomass accumulation, percentage of bare soil, percentage of litter cover or basal plant cover.”
Olson said the diversity of plant species was improved by four consecutive years of prescribed fire in August or September compared to April. In a subsequent three-year study, the performance of grazing yearling cattle was found to be similar between pastures burned in April versus those burned in August.
“During the growing season and when within prescription, fires travel slower and have less overall intensity due to the fire needing to use significant energy to drive off the moisture from the previous year’s fuels along with consuming the current green fuels,” Carlson said. “These burns will produce more smoke and steam comparatively so one must take this into account by only burning on days when the winds will push smoke away.”
There are several things to consider when planning a summer burn:
• One must have an objective and have the proper site conditions, such as appropriate amount of previous year’s vegetation that can carry the growing season burn.
• The objectives, weather conditions, notifications, maps, and safety elements need to be built into the prescribed fire plan -- and followed.
• Consider the current moisture level in the soil and the overall weather trend. It is good to have adequate soil moisture so the grasses will resprout and grow to provide cover for the winter months.
• Fire breaks must be properly prepared.
• Growing season burns can be more exhausting for individuals due to high temperatures and humidity. Take frequent breaks to cool down as needed.
Growing season burns are starting to get more attention due to the benefits they provide. When done properly, these burns are another tool for natural resource managers.
Alicia Boor is the agriculture and natural resources agent with K-State Research and Extension – Cottonwood District. Contact her by email at aboor@ksu.edu or call 620-793-1910.
