* Note for Media: A revised photo is included with this news release. 

The recent wildfires that affected more than 110,000 acres in northwestern North Dakota have been mostly contained, but the aftermath of the wildfires bring soil erosion concerns. The most immediate consequence of fire on landscape productivity is the potential for soil erosion, say North Dakota State University Extension experts.

Wildfires significantly increase the risk of wind erosion and land degradation in crop and rangeland areas by destroying plant cover and the protective residue/litter layer. Vegetation, including crops and native grasses, helps anchor the soil and break the force of wind. Without plant cover, soil becomes loose and more susceptible to erosion. Additionally, plant roots stabilize the soil structure, while stems and leaves shield the surface from wind.

When a fire occurs, this natural protection is lost, leaving the soil vulnerable to erosion from wind, especially during the dry and windy conditions northwestern North Dakota is currently experiencing.

“Another common issue following wildfires is soil hydrophobicity,” says Carlos Pires, NDSU Extension soil health specialist. “In slow-moving fires, the combustion of plant material produces a gas that infiltrates the soil profile. As the soil cools, this gas condenses, forming a waxy coating causing the soil to repel water and reduce infiltration. However, this should not be a major problem for land managers in North Dakota, as most of the wildfires in the region can be characterized as rapid fires.”

“With the current conditions, controlling soil erosion is a great challenge when you consider the lack of soil moisture, strong winds, and low temperatures,” says Pires. “The number one erosion control technique is reseeding the severely burned areas with native grass (rangeland) or cover crops (cropland), however, this approach is impractical this time of the year.”

Potential options for reducing erosion on fire-affected lands include increasing surface cover through the application of manure or other residues, or increasing surface roughness to slow the wind velocity on the soil surface. Further, any opportunity to retain snow will be critical for reducing soil erosion.

“Land that was spared by the fires and retained surface cover will likely accumulate eroded soil from nearby burned fields,” says Brady Goettl, NDSU Extension soil scientist. “Some landowners have reported soil “dunes” as deep as 18 inches in stubble fields and ditches.”

While this accumulating soil will create field variability and concerns with soil water dynamics, the best approach will be to allow accumulated soil to remain undisturbed until spring. Any attempt to level the soil this fall will only increase erosion potential, share the Extension specialists.

“Due to the nature of these fires, the recommendations and emergency practices to mitigate erosion should be addressed on a case-by-case basis,” says Goettl.

Landowners experiencing severe soil erosion issues should contact their county NDSU Extension agent to receive information tailored to their situation. Find your local Extension office at ndsu.ag/countyoffice.

NDSU Agriculture Communication – Oct. 29, 2024

Source: Carlos Pires, 701-231-7838, carlos.pires@ndsu.edu

Source: Brady Goettl, 701-367-2441, brady.goettl@ndsu.edu

Editor: Kelli Anderson, 701-321-6136, kelli.c.anderson@ndsu.edu