Skip to main content
You are the owner of this article.
You have permission to edit this article.
Controlling weeds, adding nutrients important in forage production
top story

Controlling weeds, adding nutrients important in forage production

Alfalfa cutting

Freshly cut alfalfa sits in a field east of Canistota, South Dakota in late May 2020. 

It’s every rancher’s goal to learn how to create more forage per acre, and doing so means resolving tough pasture issues like fescue, weeds, stocking rates, and increasing plant diversity.

Issues that interfere with healthy forage production were address in a webinar hosted by the University of Missouri Extension April 5.

Fescue contributes to several problems. The drought-tolerant grass was introduced to solve erosion problems. But an unmanaged pasture with infected fescue can cause lower conception rates in cattle.

“Fescue hosts an endophyte (fungus) that can produce toxic compounds called ergovaline,” Terry Halleran, field specialist with the University of Missouri Extension. “When cows eat it their body temperature goes up and they won’t eat as much. Fescue toxicity can be a problem.”

Toxicity can cause a cow to lose a back foot, which could slough off in a condition known as fescue foot. It can also lessen cattle’s conception rate and reduce the average daily gain on calves because the cows don’t milk as well.

Forage specialists are looking at ways to address a problem with fescue. Most solutions will require good management and sometimes quite an investment. Producers may have to take the fescue out and look to seeding legumes and other grasses in hopes of decreasing the amount of fescue in the pasture below 50%.

“Most people here aren’t going to take that fescue out, so we have to find ways to work with this,” Halleran said.

Weed infestation can occur from pastures being overgrazed. The soil carries a large amount of different types of seeds, and some are weed seeds. When livestock overgraze, sun and water get to the bare spots, giving weeds a chance to sprout and out-compete the grass.

“For people who refuse to spend money on lime, fertilizer and weed control, then those weeds native to the area will explode because they’re in the ideal condition to do so,” Halleran said.

He advised that cool season grasses need a soil pH of 5.8, but if legumes are included the pH should be 6.0. Based on a fertility survey of 26 Missouri pastures in 2015, a 1-unit increase in soil pH corresponded to about 3,100 fewer weeds per acre.

When a crop like hay is taken off the field, then nutrients are also removed. Hay can remove 80% of nutrients added to the field.

“If you mow, rake, bale then you’re taking those nutrients from that farm to another farm where the hay is fed,” Halleran said. “Removing hay depletes the ground, and weeds start appearing.”

He advises taking a soil test and following recommendations for what type of nutrients are needed.

Controlling grazing, is also important in order to keep nutrients.

“We want to put nutrients where we want them,” Halleran said. “You want to move cattle into paddocks, have them eat what’s in front of them and go to the bathroom right there and then move them to the next paddock – which allows us to control the grazing height of the grass.”

He suggests keeping cool season grass at 4 inches tall. The rule of thumb: if you can see the muzzle of the cow, get them out – it’s too close. From 4-15 inches is the perfect amount to graze when the grass is lush, Halleran said.

Reporter Amy Hadachek is a two-time Emmy Award winning meteorologist and a storm chaser who earned her NWA and AMS Broadcast Meteorology Seals of Approval. She and her husband live on a diversified farm in Kansas. Reach her at

AgUpdate Daily Headlines

* I understand and agree that registration on or use of this site constitutes agreement to its user agreement and privacy policy.

Reporter Amy Hadachek is a two-time Emmy Award winning meteorologist and a storm chaser. She and her husband live on a diversified farm in Kansas. Reach her at

Related to this story

Find the equipment you're looking for

Get up-to-the-minute news sent straight to your device.


Breaking News