Grazing Management After a Wildfire

By Jerry Volesky

There have been several wildfires this spring that have affected range and pasturelands across Nebraska and that threat will continue until we have new, green grass growth later this spring. Although the immediate aftermath of a fast-moving fire can look quite devastating, the perennial pasture grasses are resilient and will recover, especially since they are still dormant.

On sandy soils, one of the key impacts of a wildfire is the loss of plant residue and litter that protects the soil surface. This residue is important for reducing wind and water erosion and the loss of soil moisture.

An important grazing management recommendation following a wildfire is to delay turnout, possibly as long as one month, but this can be adjusted depending on rainfall. This simply allows grasses to accumulate more grow before being exposed to grazing.

Secondly, stocking rates should be reduced with the objective of leaving adequate residue, which will become litter on the ground. This is to replace what was lost in the fire. Rainfall in May and June will be most critical and should be the guiding factor affecting any of the above management decisions.

Confounding any grazing management plans we might have are the fences that may have been significantly damaged. Additionally, there are pastures that may have been only partially burned. On a pasture that has been partially burned, it is known that cattle will prefer to graze the burned portion, resulting in much heavier grazing on that area compared to the unburned portion. Temporary fencing to exclude burned areas early in the season may be a solution but is often impractical. 

It is not uncommon to see a greater number of annual weeds show up in a pasture after a fire. While this may look concerning, these weeds can be useful and have some forage value or will turn into residue and cover at the end of the season.

Spring Planted Alfalfa

By Todd Whitney

Alfalfa can be successfully seeded in the spring or fall depending on field weed pressure, moisture conditions and timing. Once established, perennial alfalfa plants can complete well with weeds. However, first year stand establishment can be a challenge when moisture is limited and weed pressure is high.

If herbicide resistant weeds are currently growing in fields, then light tillage may be needed to control these weeds while creating a firm seedbed for alfalfa drilling. Also, combining light tillage plus herbicide may be a best management seedbed preparation practice.

Since new alfalfa seedlings are susceptible to injury from many herbicides, it is critical to follow all chemical label instructions. Usually, the alfalfa will need at least two to four trifoliated leaves before herbicides are applied, and 2,4-D usage is not recommended. Glyphosate-tolerant or Round-up Ready alfalfa varieties provide more flexibility for controlling weeds currently growing in fields. Initial glyphosate application should occur between alfalfa emergence and fourth trifoliate leaf alfalfa growth stages to remove non-glyphosate tolerant alfalfa seedlings and control weeds that are present.

Our UNL "Seeding Alfalfa" NebGuide G2247 lists other steps for successfully establishing new alfalfa stands. For example, alfalfa grows best at 6.8 soil pH with a pH range from 6.5 to 7.5. Seed alfalfa between April 1 and May 15 in eastern and southern Nebraska, and sow seed between April 15 and May 15 in western and northern regions.

Overall, establishing a firm seedbed is critical for alfalfa seedlings. Target seeding depth is ¼- to ½-inch for fine-textured soils and ¾-inch depth in sandy soils. Seedlings placed too shallow will dry out rapidly and die due to poor roots. While seeds planted more than one inch deep may be unable to emerge after germinating.

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