MANHATTAN, Kan. -- Less than 4 percent of the original tallgrass prairie remains intact, and an overwhelming majority of it is located in the Flint Hills of Kansas. To protect it and keep it in its natural state, Kansas State University scientists and other prairie ecologists, say it's important to conduct routine prescribed burns.

Fire has always been a key ecological process in the tallgrass prairie. In pre-European settlement times, the prairie burned in a variable, but frequent regime (two to five fires per decade), said Walt Fick, range management specialist with K-State Research and Extension. Periodic fire is essential to the preservation and sustainability of these grasslands.

The prairie cannot continue to exist without fire, Fick said. Frequent fire increases the growth and abundance of native prairie grasses and prevents the establishment and spread of invasive woody plants.

Air quality an issue

The prescribed (planned) burning of prairie is a combustion process and, like all such processes, grassland burning releases particulates, oxides of nitrogen, carbon and other substances into the air. The reduction in air quality is an environmental downside of extensive burning, but these effects are transient and not chronic.

The temporary reduction in air quality has drawn the attention of both the Environmental Protection Agency and the Kansas Department of Health and Environment. Both agencies became concerned in April 2003, when the air quality in Kansas City did not meet acceptable standards.

Because of weather conditions in 2003, much of the Flint Hills burned during a three-day time span in mid April, resulting in smoke that hung in the atmosphere and drifted on air currents into Kansas City. The smoke caused a spike in air particulate matter. Each spring since 2003, when pastures are being burned, a significant increase in air particulate matter has been detected in the Kansas City area, Fick said.

Knowing the environmental value of tallgrass prairie burning, EPA and KDHE officials sought the advice of K-State Research and Extension, the Natural Resources Conservation Service, and the Kansas Department of Agriculture. A committee was formed to study and recommend ways to manage smoke emission from burning.

"This issue can be addressed through voluntary practices and improved management," said Kansas Secretary of Agriculture Adrian Polansky.

How to minimize smoke drift problems

Committee members acknowledged that dry conditions across the state have left many areas under a burn ban, but the members are making the following recommendations to landowners who are considering burning tallgrass prairie if sufficient rain is received prior to April burning times.

These recommendations should minimize the amount of smoke particulate matter drifting into major metropolitan areas:

  • Wind speed: Wind speeds of 5 to 15 miles per hour are best. As winds reach 20 miles per hour, the chances of controlling a fire in a good pasture fuel-load are slim.

  • Lack of wind speed: No wind means that a breeze will come up in a few minutes, but you don't know from which direction. A 5-mile-per-hour breeze is more dependable.

  • Relative humidity: Plays a big part in conducting a good controlled burn. Relative humidity of 40 percent to 70 percent is acceptable. Below 40 percent puts the area into a high fire danger situation and controlling fires can be difficult. Above 70 percent slows the burn because it hampers getting the fire to carry through the fuel, and smoke may be increased.

  • Air temperature: Should be 55 to 80 degrees. The cloud cover should be less than 70 percent for safe burning. Clouds will trap smoke and a minimum ceiling of 2,000 feet is required. Both conditions are necessary to get rid of the smoke. Picking a day when the smoke goes up high, indicating a good ceiling, is important.

  • "Burning is a necessary practice of grassland management, but it's important that land owners take the time to prepare, have the right equipment, enough help, and pick the right weather conditions to conduct the burn," said Mike Holder, K-State Research and Extension agent in Chase County and a member of the committee. "Counties vary on what they require for controlled burning. Some require a permit, others just give permission the day of the burn."

    Holder advises those who are considering a controlled burn to check with their local sheriff dispatcher to find the requirements for the county in which they plan to conduct a burn.

    Burn mid-April for best stocker cattle gains

    The proper timing of burning tallgrass prairie has been debated by experts. But 40 years of research by K-State indicates that burning in mid April (early April in southern Kansas and late April in northern Kansas) will result in the best gains in stocker cattle. These increased gains are due to increased forage quality and/or increased forage intake of cattle grazing burned areas.

    Jeff Davidson, K-State Research and Extension agent in Greenwood County noted that "not all land managers run stocker cattle. Cow-calf producers don't get the gain advantage that stocker producers do from burning. However, they should still burn every two to three years to keep woody plants from encroaching on the prairie. The timing of burns for cow-calf producers is not as crucial as it is for stocker producers."

    Acreage enrolled in the USDA's Conservation Reserve Program may need to be burned at least every two to three years to prevent woody plant encroachment. The program allows prescribed burning to occur on CRP acres between the dates of Feb. 1 and April 15. However, CRP contract managers need to check with local USDA-FSA and NRCS officials for specific guidance.

    Targeting prescribed burns earlier in the burn window may improve plant community diversity and increase habitat favored by a more diverse wildlife population, said Davidson. Native wildlife of the prairies evolved with the grassland. Fire was a critical factor in wildlife habitat development. Properly used, prescribed burning can increase desirable warm season grasses and native wildflowers. This plant complex supplies food, nesting and brood-rearing cover for ground-dwelling birds.

    "Several things should be considered before lighting that match," Davidson said. "Not all burns are the same. Timing is important, but the weather conditions the day of the burn can affect the degree of brush control obtained, completeness of the burn and smoke particles emitted."

    A K-State publication, "Prescribed Burning as a Management Practice," offers details of burning. More information about prescribed burning is available at county and district K-State Research and Extension offices or here on the Extension Web site.

    Be aware of burn bans

    Anyone considering a planned burn of the prairie or any other type of burning should be aware of local and statewide regulations.

    The Kansas County Burn Ban Alert map, available on the Kansas State Fire Marshal Web site, indicates counties that have implemented bans on all burning. The map is updated on a daily basis as counties institute control measures or as they drop them. This will most likely be as the dry conditions improve. The State of Kansas is experiencing dry conditions to vegetation that can be considered flammable and hazardous. State officials are encouraging citizens to be careful and help prevent fires, by not discarding smoking materials along roadways or into grassy areas. If open burning is allowed in your particular area, do so with all precautions.

    SOURCE: K-State Research and Extension news release.