Move animals through grazing system based on forage production

DAVIS, Ill. — Plant succession is a process where one plant community replaces another.

“This can happen in a large or small timeframe,” said Kathryn Seebruck, crops educator for University of Illinois Extension. “In a pasture, this change can occur due to an environmental change, weather change, soil erosion issue or overgrazing.”

Positive succession is when a desired species replaces other desired species.

“Typically it is going to be undesirable species like weeds that will take over and that process is retrogression,” said Seebruck during a presentation at the Illinois Forage Expo, organized by the Illinois Forage and Grassland Council.

“That change to a less desirable species is what we want to avoid,” Seebruck said.

“When you have retrogression occurring, you want to determine a cause and from there you can come up with a plan to reverse it,” she said.

Grazing management is important to give plants in a pasture the opportunity to rest, rejuvenate and revive.

“The benefit of rotational grazing is you will have more productive pastures,” said Seebruck during the expo held at the Eric Stiegler and Don Brown farms. “But there are watering and fencing costs involved with that.”

Cattlemen can use a formula to determine the number of paddocks needed in an operation.

“Take the days of rest divided by the days of grazing and add one,” Seebruck said.

“If you are utilizing 10 days of grazing and 30 days of rest, you will need four paddocks or pastures,” she said.

“Make sure you are moving livestock by the forage and not by the calendar,” she stressed. “Just because you’ve allotted 10 days doesn’t mean it’s going to take the entire 10 days for the livestock to take half of the forage or maybe they will need a little bit more time to do so.”

Overseeding is a method to add more forage into a pasture, boost an area that has bare spots or add more productive species.

“I’m not talking about renovation,” Seebruck said.

“There won’t be large or immediate production increases you might see with a nutrient application,” she said. “Instead with overseeding, production increase will be gradual because the plants need time to establish.”

Overseeding will be more successful if it is done on a thin or less competitive stand.

“You might want to consider overgrazing an area,” Seebruck said.

Interseeding into an existing sod is done in the spring or late summer when the growing conditions are good.

“Typically you are going to be drilling the seed,” Seebruck said. “You can broadcast, but it is not highly recommended because it is difficult to get seed to soil contact.”

Frost seeding takes place in late winter when the ground is frozen.

“If you have heavy snow, you will probably want to avoid frost seeding, because by the time the snow melts, the distribution of the seeds will be less than ideal,” Seebruck said.

Environmental conditions can have an effect on the success of frost seeding.

“It will depend on the freeze-thaw cycle, the late winter snowfall and the early spring rain,” Seebruck said.

Weed control is a method of pasture improvement and proper weed identification is critical.

“Weeds are very competitive and a lot of them are very prolific seed producers,” Seebruck said. “So, it is really important to get ahead of the seed production.”

Biennial weeds take two years to complete their life cycle.

“The two years look very different for these species,” Seebruck said. “In the first year, they will have vegetative growth only and in their second year they switch to reproductive growth.”

Many biennial weeds grow a basal rosette of a spiral of leaves that are very low to the ground.

“Mowing a first-year biennial will not be effective,” Seebruck said. “Also the first year, the weeds send all their reserves to the very robust taproot that will help them overwinter.”

In the second year, the taproot sends the reserves up the plant and the plant will bolt.

“Now you have a weakened root system and you have something you can mow,” Seebruck said. “Those two things combined will make mowing much more effective for a second-year biennial than it would be for a first-year weed.”

Perennials take multiple years to carry out their life cycle.

“So, a contact herbicide won’t do great because perennial weeds have robust root systems that allow them to overwinter,” Seebruck said.

Some weeds can be grazed to control them especially in their early vegetative stage when they are more palatable and they have higher quality.

“But once they have been grazed, you will want to come back in and clean up the weeds that were not controlled by grazing,” Seebruck said.

Proper timing and maturity are important when controlling weeds by mowing.

“All weeds are easier to kill, the smaller they are and this will only control erect weeds,” Seebruck said.

The best timing for herbicide application is when the weeds are young, small and actively growing.

“Be careful about how you select your herbicide products because not all are created equal and not all are going to be appropriate,” Seebruck said.

“Always consult the herbicide label because the label is the law and you need to abide by what is listed on the label,” she stressed.

“If you have weed removal, you’re going to be left with some bare space so make sure you seed your desirable species after that,” she said. “If you don’t do anything after you remove those weeds, more weeds are going to come in and take over that same area.”