IRVM: Brush Control and Controlled Burns

Brush Control

Yet another aspect of I.R.V.M. in Mahaska County is the removal of roadside brush. This does several things for both the roadside and the road.

The brush in road ditches creates problems for the roads. They shade the roads during the winter and spring months delaying melting and drying which makes slick spots on the roadways. Brush also lets the road drift in when the snow starts blowing.

In the last few years, we have gone towards using heavy equipment in our brush removal endeavors. Using this system, we can clear miles of roadside brush each year. The machinery eliminates the need for crews to cut the brush up into manageable pieces.

Entire trees are now carried to piles and burned. Stumps are to be cut as low as possible and chemically treated to prevent respouts. This prevents vehicle damage if the car leaves the road. Our brush removal has improved significantly. During the summer months we also target problem brush by foliar spraying. Each year we travel every road in the county looking for brush and noxious weeds that need to be spot sprayed. We also use backpack sprayers in the winter months to target problem areas with basal bark and thin-line chemical treatment.

Controlled burns also help us in our quest to eliminate brush. It is all part of the integrated idea. There is no one right way. But, if we use these techniques in coordination with one another, we realize greater success.

Controlled Burns

The ability of fire to keep grassland systems free of weeds and brush is being re-discovered by roadside managers and prairie enthusiasts, alike.

Fire destroys brush, especially small brush, by damaging the growing point near the ground. With the growing point damaged, the brush is rendered helpless for that season.The following season, the brush generally suckers back near the dead stalk. These suckers are coming from the root reserve. They are tender and susceptible to herbicide application or another controlled burn. The second burn usually eliminates any stragglers. While the fire is killing the brush, it is also doing something very important to the grasses. It promotes the growth of the grasses by blackening the soil, adding nutrients, increasing soil temperature and decreasing competition.

With controlled fire, not only are you knocking back the undesirable vegetation, you are setting the stage for the success of your desirable species.

The native prairie species we plant are adapted to fire at any time, but even non-native, European stands of brome or canary grass can also benefit from a burn timed very early in the spring, or very late in the fall.

Burning was once a time honored tradition years ago on the family farm. Firebreaks were plowed and a burlap bag soaked in kerosene was the torch. Scoop shovels were used to swat out the fire and the whole family got involved.

Today, most roadside managers in Iowa are certified wildland fire fighters with hours of controlled burn experience under their belts. Each burn is designed specifically according to fuel load, wind speed, relative humidity, fuel moisture and other site conditions.

When burning roadsides, smoke on the road is our main concern. We use techniques such as ignition patterns to help us move smoke off the roadway. We also have warning signs, fire suits, water packs and pump trucks to better control flames with.

Drip torches help us make sharp, accurate fire lines and portable weather stations help us know when to adjust the controlled burn for rapidly changing wind or other factors. It is high-tech and a lot safer than it used to be.

The concept is still the same. The safety stakes are just higher these days. Burning is our cheapest and most effective way to, "blanket-treat" today’s roadsides. It is an effective tool and we will continue to use it with our integrated approach.