-Farm News photo by Doug Clough
Beth Doran, foreground and holding a pasture measurement stick, talks to a group of cattle producers at a pasture walk to the east of Castana. Doran is a 17-county beef specialist for ISU Extension. The event was held at the Iowa State University Western Research and Demonstration Farm.

CASTANA — On June 26, 46 cattle farmers from numerous northwest Iowa counties gathered for a pasture walk. The purpose of the workshop was to explore, while in the farm’s pasture, forage recovery, weed control, and soil fertility.

At the first paddock stop, Beth Doran, ISU Extension beef specialist, addressed the farmers. “Both Woodbury and Monona counties are tied for the distinction of suffering the worst during this drought,” said Doran. “That’s why we are here to concentrate on drought management and recovery.”

Both Woodbury and Monona counties are in the 17-county area where Doran serves.

The event was sponsored by the ISU Extension with support by the ISU Western Research and Demonstration Farm. Speakers were Rich Pope, former ISU integrated pest management specialist; Chris Beedle, manager of Western Iowa Research and Demonstration Farm; Leah Ten Napel, ISU Extension field agronomist; Pat Corey, district conservationist for Natural Resources Conservation Service; as well as Doran.

Chris Beedle, farm manager, kicked off the event, explaining his efforts to nurture the demonstration farm’s pasture.

-Farm News photo by Doug Clough
Rich Pope, former ISU Integrated Pest Management Specialist, demonstrates how to use a sweep net to collect insects on pasture ground.

“We take 52 fall calves during the summer to graze on our pastures,” said Beedle. “We have 62 total acres of pasture, and we have three paddocks in two different areas where we do rotational grazing in three-week periods. Given that we were 22 inches short of rain, we were able to do better on our pasture than we thought we would.”

The demonstration farm’s cows travel more than usual for water due to the drought.

Beedle supplement feeds with three pounds of cracked corn, three-quarters of a pound of

protein pellets, mineral block, and hay.

Doran spoke to rotational grazing during drought.

“If you want to spare pastures,” she said, “you’ll want to rotational graze. You’ll notice in this pasture that it isn’t grazed down tight. The good standing rule is to take half and leave half with it. If you take this Brohm grass any lower than four inches, you’ve taken most of the growing point. You’ll also want to make sure that you have a good root system.”

Doran made sticks available to the attendees, which showed the length grass should be to turn cattle out, when to stop grazing, and when a pasture should be given a time for rest.

Pat Corey, district conservationist, said he would expect a lot more regrowth in a normal year

after three weeks of rest.

“The bottom and lower areas have greened up a lot faster,” said Corey. “Those are more shaded and what little rain we’ve had goes that way.”

Leah Ten Napel, field agronomist, spoke on fertilization.

“When it comes to fertilizing our pastures, it’s really important that we manage based on production,” she said. “We aren’t going to manage our phosphorus (P) and potassium (K) the same way we do our field or row crops. Soil tests are a great tool for managing a pasture. We don’t see a return on investment when we are fertilizing above optimum levels. A lot of the P and K are put back into the soil by the animal. If you have over a third of legumes in your pasture, we do not recommend applying any nitrogen.”

Ten Napel also noted that it’s not common to lime pastures, but the ISU Extension recommends the pH be at the 6.0 level.

Rich Pope, former ISU integrated pest management specialist, spoke on competitors for forage.

“Fall army worms can be found typically in late summer and early fall,” said Pope. “You’ve got

to catch these early on, so you can act quickly before devastation. The larvae of a fall army

worm have a black head; on the head capsule, it has a y-shaped set of structures.

“Another troublesome insect is a true army worm, which is similar in their life cycle to a black

cutworm that we fight in cornfields. These insects don’t overwinter; they count on moths to fly

in during the spring. ISU Extension does pheromone tracking to see when those moths arrive,

because they want to have sex, lay eggs, and create the true army worms. Pheromone traps

catch all the boys who are looking for love in all the wrong places, allowing us to know when we

must combat this worm.

“In northeast Iowa, they were starting to see true army worms in mid-June; on these, the head capsule is yellow with a bunch of fine reticulated lines that are a little darker — black chevrons will also be on the four prolegs. These worms love rye grass.”

Pope said that using a sweep net to get samples of insects in the pasture’s forage is a good

forewarning system.

“I would expect to find some grasshoppers this time of year as they over-winter in Iowa by placing a column of eggs in the ground to hatch in late spring,” said Pope.

“We’d prefer a wet period in the spring that would drown the eggs greatly reducing the

population, but we don’t have that luxury during a drought.” Pope suggests sweeping a nine-square-foot area to get an appropriate sample; he suggests that 15 to 25 grasshoppers contained in the net would meet an economic threshold requiring action.

Doran highlighted the main points of the evening’s walk.

“First, be a pasture producer and then a cattle producer; a good pasture benefits the cattle,” Doran said. “Second, be prepared to adjust your pasture management during times of drought: reduce stocking rate, wait to turn out when brome plants are six to eight inches tall, rotational graze, allow rest and recovery time for the plants to regrow, and avoid overgrazing. Finally, think ahead on pasture fertility, weed control, and scouting for damaging insects. All of these things will contribute to a healthier pasture.”