Farmers look for any edge when it comes to weed management. While issues in crop fields are heavily discussed, managing prairie land can be just as important to benefit wildlife.
For CRP, management means turning to a field burn in some cases.
Burning fields is particularly popular in natural resource conservation tactics, said Dana Kellogg, a natural resources manager with Linn County, Iowa. When the timing and weather is right, his days get busy.
“You’ll get things lined up and then the humidity might be too high or it rained the night before,” Kellogg said. “You can’t plan very far in advance.”
Kellogg said spring still tends to be the optimal time for prescribed burns, but over the years that timeline has spread out to the point where fall burns are showing plenty of benefits. The end goal is always to leave a little cover on the ground for winter, he said.
“For control of woody species — keeping shrubs or trees out of your prairie — it seems to work a little better for those types of things,” he said.
Kellogg said burns are efficient and effective in many cases, simply because the fire can eradicate a lot of material at once. However, working with fire means additional safety measures. He said any farmers doing a burn on their CRP or prairie land need to take multiple factors into account.
“Look at the climate and weather conditions as well as having the right manpower to do it,” he said. “The main things to think about are not letting it go off their property to someone else’s. Have good firebreaks installed before you burn and watch the smoke management.
“In a small, rural county it’s probably not as big of a deal compared to a city or a town. Our minimum crew is about four people, but we can have as many as 10 or more if it’s a bigger job.”
Prashant Jha, Iowa State University Extension weed specialist, said this tactic is good for non-production land, but likely won’t be an option for fields with corn or soybean. Still, there is a need for alternative weed management in row crops.
Jha said the lack of moisture seen by many in Iowa caused herbicides to be less effective this growing season, leaving weeds such as waterhemp and volunteer corn to pop up in many fields this season. He said with how prevalent some issues were, preparing for 2022’s growing season should begin this fall.
“We had some more storms down corn, especially in northwest Iowa, so it’s going to be an issue next year as well,” Jha said.
In crop fields, clearing out the seedbank is key, and Jha said using methods such as the seed destructor and electrification are getting more attention. With continued research, these will start to become more available to farmers. He said equipment like the seed destructor has been able to kill more than 95% of waterhemp seeds in a field. Electrocution is also a good late-season effort that could be expanded.
“We definitely need to diversify our weed control tactics,” Jha said. “Managing the seedbank is very crucial. We have almost no escapes in corn because it grows so tall, but in soybeans our options are so limited. Weed control technologies are going to be more popular to manage this.”