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Department of Agronomy

Kansas State University

1712 Claflin Rd.

2004 Throckmorton PSC

Manhatan, KS 66506

785-532-6101

agronomy@ksu.edu

Extension Agronomy

Management following a wildfire

The dry conditions throughout much of Kansas have led to an increased danger of wildfires. If a wildfire occurs, the ability of rangeland or tamegrass pastures to regenerate forage depends on precipitation amounts, the time of year that the fire occurs, the water infiltration ability of the soil, and management factors following the fire.

Wildfires can damage grasses, reduce stored food reserves, reduce moisture infiltration, increase evaporation and runoff, lead to erosion, create grazing distribution problems, and lead to an infestation of noxious weeds.  Wildfires differ from prescribed burns as the land manager doesn’t select the time of burning or the weather conditions under which to conduct the burn.

The crowns of grass plants often survive a wildfire and will regrow, but some can be damaged if the fire occurs when soil and air conditions are extremely dry. If plant litter remains after the fire, less damage will have occurred to the plant crowns, and soil conditions will be better. Evaporation and runoff may be increased if the fire occurs when the grasses are not actively growing. Bare soil may lose at least one-half inch of moisture per week through evaporation. The higher the clay content of the soil, the greater the potential for puddling and runoff.

A. Native warm-season grass rangeland

When wildfires occur between late June and frost, the major consideration is to protect the plants from overuse. Immediate removal of the grazing animals is usually necessary. This will permit regrowth and allow plants to accumulate food reserves before winter. Wildfires occurring between fall and mid-March leave the soil bare until spring growth. Forage yields may be reduced, and a reduction is stocking rate is advised.

Between mid-March and June, wildfires generally do not reduce forage production. However, if conditions are dry, regrowth will not occur and stocking rate must be reduced. Wildfires at this time may change plant composition of the grazing land.

On sandy soils, blowouts should be controlled as soon as possible. Mulching with manure, straw, or hay free of noxious weeds, along with reseeding can stabilize the blowout area. Fencing of blowouts will restrict livestock traffic and speed recovery.

Several grazing management options exist after a wildfire. If a wildfire occurs where prescribed burning is practiced, burn the areas that were untouched by the wildfire in late spring, when the desirable grass species have 1 to 1.5 inches of new growth. This will encourage grazing of the entire pasture. Observe where the animals are grazing, and use grazing distribution tools such as salt, mineral, and oilers to attract cattle to underutilized areas.

For forage plants to recover, it usually will be necessary to reduce stocking rates on the burned area.

 

Area

Year after wildfire

Stock at:

Flint Hills and East

1

75-85%

 

2

Normal

Central Kansas

1

65-75%

 

2

90-100%

 

3

Normal

Western Kansas

1

50%

 

2

75%

 

3

Normal

 

Note: During lengthy droughts, use lower stocking rates than those listed in the chart. The main concern is the inability of the plants to regrow. The plants must be given the opportunity for regrowth during drought.

If a wildfire occurs where prescribed burning is not practiced, management decisions should be based on when the grassland was burned, how much of it was burned, and where livestock water is located.

Example 1: If there is a livestock-watering source in both the burned and unburned portions of the grassland, divide the burned and unburned areas (using an electric fence, for example) and reduce the stocking rate in the burned area.

Example 2: If there is only one livestock-watering source in the grassland area, the decision is whether to manage the burned or the unburned area. If the unburned area is larger, separate the two areas with an electric fence and stock the unburned area at the normal rate. If the burned area is larger, either manage only the burned part by reducing the stocking rate or establish an alternate water source, fence the area, and reduce the stocking rate on the burned portion. If the sole watering source is in the burned portion, the unburned portion would not be utilized unless the area was fenced and another water source established or a lane is fenced off to allow watering from the unburned area.

Example 3: If only a small portion of the grassland is burned, fence it off and reduce the stocking rate on the unburned portion accordingly.

Mowing unburned areas in the early spring can encourage livestock to move from the burned area. However, don’t mow in August or September. Early intensive grazing is another option for burned areas. Removing all livestock from the grassland by mid-July provides late-season rest and time for the desirable grasses to replenish root reserves.

Patch-Burn Grazing:

Another option to consider is patch-burn grazing.  Research in eastern Kansas has shown that burning a third of a pasture will not reduce stocker gains compared to burning the entire pasture.  Animals will graze the burned area more frequently and cause some temporary shifts in plant composition.  The key is to burn a different third the next year and so on.  Different ages of burn in a pasture will increase plant diversity and may be a good wildlife management tool.

B. Tamegrass hay meadows

Hay meadows burned by wildfires will probably produce less hay. To return hay meadows to their former production, cut the meadow in early to mid-July to allow regrowth and replenishment of root reserves.

 

Walt Fick, Rangeland Management Specialist
whfick@ksu.edu