This article has been revised to reflect the following correction: Title and job descriptions were updated.
SIOUX FALLS, S.D. (KELO)– Windy days can cause extreme amounts of topsoil to blow off of fields where there is no residue left on the ground.
When a farmer experiences a field fire, there are two effects that come to mind for Dennis Hoyle, Founding Board Member of the South Dakota Soil Health Coalition. Hoyle also operates his own farm in Edmunds County, South Dakota.
“It bares up the soil,” Hoyle said. “We never want to be able to see our soil and if you burn all the vegetation off of it, obviously it’s exposed. Depending on how hot the fire is and how long it’s there, it could also have an effect on the biology in the soil.”
Hoyle said there are three keys that come to mind when it comes to soil health: biology, organic matter and water infiltration, all of which are affected when there is a field fire.
Video of a field fire north of Brandon, South Dakota, on Monday, March 29
A part of the soil health idea is to mimic the native rangeland, Dave Ollila, South Health Specialist for the South Dakota Soil Health Coalition and producer from Newell, South Dakota, said.
Fires tend to affect no-till operations more than those using conventional tillage because the no-till ground has residue left on it that producers would like to keep there, Hoyle said. Tillage pretty much strips away that layer of residue anyways.
“A raindrop should never hit bare ground, never,” Ollila said. “It should always hit some residue and then roll over, then be absorbed into the ground.”
If there is cover on the field, you have a much better chance of having rain go into the soil, Hoyle said. If you don’t have residue and there is a hard and large amount of rain, the water will run-off and take soil particles, fertilizer, pesticides or other things with it and run into a stream of water that eventually will make its way to a city and be used as drinking water.
“Healthy soil becomes a filter; unhealthy soil becomes a source of pollution,” Hoyle said. “If you can put it in the ground, it will make the water cleaner. So, it’s a win for the soil but it’s also a win for the water.”
Biology found in the soil, also doesn’t tend to like heat, Hoyle said.
The amount of time it takes for the soil and the biology found in the soil to recover after a field fire depends on several factors. It depends on how hot the fire was and what happens after the fire, Ollila and Hoyle said.
If you get nice, gentle rains and cloudy days, recovery will be faster than if there are hot, drier days, Hoyle said.
“Tillage is like a tornado going through a town, you can fix it back up, but it’s going to do it some damage,” Hoyle said. “Well, if a tornado goes through a town every other day, it’s going to be hard to make any progress. So, if you have lots of hot days, it will be hard to do that.”
When they experience fires on the western side of the state where a lot of Cheatgrass has invaded a majority of the desert type prairies, the Cheatgrass burns so hot that it sterilizes and causes the sand to become glass-like, Ollila said. That creates a hard surface area and even when it does rain, it can’t get through. It also sterilizes the soil, killing off the microbiology, which takes years to recover from.
It takes a long time for the topsoil to recover after windy days like we have experienced across KELOLAND the past few days.
After experiencing a field fire, if the producer has lost the residue and the biology, the fertility needs would be greater, Hoyle said. There is not an insulating layer to keep the soil from drying out. Unless there are very timely, lighter rains, producers will probably suffer a lot and are probably going to have to replace something because the organic matter that would’ve provided something to the soil isn’t there anymore.
By losing that residue, the farmer has also lost their snow catch, Ollila said.
“For us, having snow catch acts as not only an insulator…it also insulates and protects the ground over the wintertime,” Ollila said. “Winters are horrible out here and notorious for pulling moisture out of the soil and that’s where that residue and having the stubble, the vertical structure to catch all that snow, makes a big difference.”
As far as the outlook for fires this coming year, the weather suggests that it’s going to be warm and dry early, might break down and get a little moisture mid-summer, so Hoyle said he thinks there is some real possibility for some fires.
“It’s warm and dry. We are having fires and blowing dust in March; that’s not the time of year we are supposed to be having fires,” Hoyle said.
Causes of field fires
Field fires have multiple causes, including lightning, equipment or a cigarette thrown out a window, Hoyle said.
Sunflowers are notorious for creating that electricity in the air that they can spontaneously combust, Ollila said.
Hoyle said that millet is another crop that can cause fires. But, if you get a hot bearing, just about anything will burn.
“A lot of it has to do with the relative humidity at the time, just like these prairie fires out here,” Ollila said. “If you’ve got a July where you’re combining and there just hasn’t been any rain and you have nothing out there but dry, dry that’s a lot more likely to ignite a fire than if you’ve got a higher degree of humidity on some of them when you’re struggling trying to get your moisture down and get the crop out. Every year is different.”
Blowing dust on windy days
While fires tend to be unpredictable and hard to prevent, Hoyle said, blowing dust reflects somebody’s management decisions.
“We know it is going to get dry again, and we know it’s going to get windy and sometimes those two are going to line up together and we’re going to go through what we’ve just gone through the last couple days,” Hoyle said.
“You can’t replace topsoil at the rate you lose it if you’re scarring the land,” Ollila said.
Especially when we have the science and the technology to understand it now, there’s no excuse not to, Ollila said. Hoyle said no-till is a 35 year technology, it is not new anymore, it’s been proven for a generation.
Hoyle and Ollila walked KELOLAND News through the benefits of implementing no-till practices on an operation.
Having blowing dust can cause problems for people and make driving conditions dangerous, Hoyle said.
“We just got to keep the soil where it belongs,” Hoyle said.