If producers are dealing with foxtail barley, there’s more going on than just a new weed.
“Foxtail barley growing in a field usually means that there’s something happening in that field that’s restricting the growth of whatever crop is supposed to be there,” said Elaine Moats, regional crop specialist with Saskatchewan Agriculture.
The perennial weed is native to North America and a wild relative of domestic barley. It is flourishing this year in parts of the Prairies, mainly for two reasons: high soil moisture and soil that is naturally saline.
Two years of high moisture have brought salt to the soil surface, which has created areas prone to foxtail barley infestation.
Moats said southeastern Saskatchewan and parts of Manitoba are seeing a good crop of foxtail barley. Prolonged excessive moisture and saline soil have been good for germinating the bunch grass, which is known for its tolerance of extreme environmental conditions. Many gardeners beautify their beds with the silvery heads that blow in the breeze.
“Mother Nature abhors a vacuum,” Moats said.
“She always wants to put something on the ground to cover it up and protect it. Because of that, we have a good seed bank of foxtail barley around. The seeds can blow around in the wind and it can establish very rapidly.”
Foxtail barley particularly tolerates salinity and is able to grow where annual crops such as wheat or barley can’t survive.
Moats said it becomes a land management issue.
“In annual cropping and continuous cropping, you can move the salts up and down in the soil profile, but you don’t make them go away,” she said.
“So you’re managing where they are in the soil profile so you can have successful crop production. On fields that are very prone to salinity or have high levels of moisture, moving salts underneath the soil surface, sometimes you have to go to perennial cropping just to use that moisture. You’re using the plant as a pump, to pump water out from a lower depth and then leaving the salts down at that lower depth.
“The degree that you can manage soil moisture then allows you to also manage the plant material that grows, including foxtail barley.”
One control option is to graze the weed early in the year before seed heads are formed.
“It’s very palatable to livestock and weakens the plants so that you get a chance to then establish other forages in those areas,” she said.
“Managing the time of grazing on some of those foxtail barley areas in pasture situations has actually proven to be one of best ways of managing foxtail barley and eventually kill it out.”
Foxtail barley is a weak, short-lived perennial that is not competitive with other species. Weakening the plant makes it easier for other plants to move in and compete with it. Seedlings are much easier to kill than a plant that’s two or three years old.
“They have an established root system and it’s not enough to kill the top growth. You have to kill the root system as well,” said Bob Blackshaw, a weed scientist and researcher with Agriculture Canada.
Spring is the time to focus on killing seedlings and controlling top growth, while established plants should be targeted after harvest, which is when herbicides move down the plant along with carbohydrates and sugars.
Continued long-term problems with foxtail barley suggest the land needs to be used for something else, such as perennial pasture, livestock feed or a hay field.
Moats said saline soil can gradually be reclaimed through zero till, continuous cropping and planting crops that have more salt tolerance.
“(It’s) trying to create that microclimate on the soil surface through zero till by not stirring things up because as you stir up the soil you cause more water to move up to the soil surface through evaporation and pulling the water (and salt) up behind it,” she said.
“So minimizing tillage, trying to keep something growing on that land and letting Mother Nature help you through rainfall and snowmelt to leach the salts down.”
A faster solution is to plant perennial forage for about three years.
“These fields usually have a good level of nutrients in the field in terms of nitrogen, phosphorous and so on.”
Moats said the shimmery weed does have a silver lining.
“It does help to use soil moisture and help to reclaim those soils,” she said.
“It’s hard for producers to appreciate that stuff, though.”