For Release April 30, 2006
Why All The Smoke?
by Chuck Otte, Geary County Extension Agent
Most likely all, or most, of the pasture burning for this year is over. A question that I have to answer several times every year is why do they burn off the grasslands? It's actually a fairly simple question, but the answers are both simple and complex. They burn off the pastures because that's what the grass is used to. Now come the explanations and complexities.
Throughout history, grasslands periodically burned. Oft times by accident, sometimes intentionally. The grasses evolved, over thousands of years, to withstand this periodic loss of foliage. They learned to keep their critical growing points underground, a trick most woody plants did not learn. Hence why this was a grassland and not a forest. Assuming normal soil moisture, or good rainfall, following a grassland burning, the grass will quickly put on new growth, just like your lawn does after you mow it.
If periodic fire is removed from the grasslands, they will surprisingly quickly start to change over to woody brushy growth and then trees will begin to dominate. Cedar trees will be the first to get established, then elms, hackberries and maples, and ultimately oaks and walnuts will predominate. This process may take 40 to 60 years to complete, but it will happen! While trees are nice and I'm a big supporter of trees, most of these grasslands are utilized for grazing livestock and cattle don't fare will trying to eat trees.
Periodic burning is a very effective method to kill out cedar trees and at least reduce the invasion of other woody plants. Mechanical and chemical control may still be needed in pastures that have been abused and neglected to completely control the woody invaders. One benefit to fire is that many of the forbs, what most people would call wildflowers, will survive the burns just fine also. Chemicals tend to be harsh on forbs. Forbs are important because many of them are eaten by cattle, providing additional nutrients and protein to their diet. Many of the native forbs are leguminous so they also provide some nitrogen into the soil of that prairie ecosystem.
While most pasture burning is going to occur from late March to late April, research at Konza Prairie over the last 25 years has shown that when you burn isn't nearly as important as just being sure that you burn every few years. There are some benefits under certain livestock production systems to burning in mid to late April every year. Livestock weight gains can be increased slightly. But we've also found that there are some ecosystem wide drawbacks to that annual late April burn leading more and more producers to focus on a once every two or three year burn.
The county and the state recognize the many benefits that come from pasture burning including, believe it or not, the reduction of wild fire risk. Therefore there are very specific rules that regulate how this is done. In Geary County, all outdoor burning is regulated by a burn permit system. Either myself or the Geary County Sheriff's Office can explain this to you. There are specific weather conditions that need to be met. We felt it was going to be too dryto burn this year, but then some rains turned that around. It is far better to burn on a day with ten to twelve mile an hour winds than when it is calm. If you remember back to mid-month, we had one of those calm days and the smoke was a problem! Yes, the burning does create some smoke issues for a few days each spring. But it's a small price to pay to help maintain these critical grasslands, and far better than the alternatives!
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