The perennial puzzle: Deciding whether to fertilize your pasture in the spring

By the U of A System Division of Agriculture

FAYETTEVILLE, Ark. — For many producers in Arkansas, fertilization in the spring isn’t so much a tradition as it is a necessity, along with crop rotation and soil testing. For pasture managers, however, the decision of whether to fertilize a grazing area depends on several factors that can change from year to year.

SPRING MEANS 'NPK' — The decision whether to fertilize a given pasture each spring should be primarily based on soil testing results. (Division of Agriculture photo.)

Dirk Philipp, associate professor of forage agronomy for the University of Arkansas System Division of Agriculture, said that it all comes down to what your soil really needs.

“Fertilizer is an expensive input to livestock agriculture,” Philipp said. “The basis for the decision when and how much to apply is a regular soil sampling plan.”

At a minimum, Philipp said, soil samples should be taken every two years.

“Not only will this help producers fertilize pastures in a more targeted fashion, it also serves to record how much soil fertility changes over time,” he said.

The Cooperative Extension Service provides cost-free soil analysis. Arkansans can find their nearest extension office in extension’s online directory.

Once growers receive their results, Philipp said, they should carefully check the recommendations, particularly the pH balance of the soil as well as the potassium, phosphorous and nitrogen levels.

“It’s important to know the acidity of your soils,” Philipp said. “It’s no problem if it’s about 6.0 — many pastures are — but avoid letting it drop too low. Bringing it back up will take time and easily require a couple of tons of lime per acre.”

Likewise, pastures that have historically been fertilized with chicken litter won’t normally be phosphorous-deficient, but growers should try and keep their levels well within the normal range so that they have “room to spare” in changing conditions, Philipp said.

“Potassium is an important element for plant cell function and one that affects plant health and productivity immediately,” he said. “Unfortunately, it is also quite expensive to apply.”

Philipp encourages growers to keep adequate potassium levels in soil, so they don’t find themselves suddenly needing to make large investments in the nutrient.

“Both phosphorous and potassium can be applied in advance, so if you know how much might be missing, you can fit those in your budget better,” he said.

Nitrogen, Philipp said, is the most limiting nutrient for plant growth and should be applied right when it’s needed.

“Keep in mind that both cool and warm season plants grow most rapidly in spring because of increasing day length and temperatures,” he said. “They will substantially reduce their growth rates during fall due to decreasing day length and temperatures.”

Timely application is important, Philipp said, but can mean different things, such as:

• Before a rain shower, when growers actually can get into the field

• After a hay cut, when large amounts of nutrients are removed

• At the beginning of the growing season, if a producer wants to apply a blend of all NPK

• If poultry litter is available, depending on one’s timeline for cleanout and delivery.

“These are all valid compromises you may have to make,” Philipp said.

When it comes to linking fertilization with pasture management, producers may need to address an additional host of issues, he said.

“When applying nitrogen to tall fescue in spring, are you able to actually graze it off and avoid fescue toxicity as much as possible? You may be better off applying it in early September for stockpiling,” Philipp said.

“Some forages, such as orchardgrass, definitely need additional nitrogen to be productive, while tall fescue is less sensitive to skipping a year,” he said. “Native warm season grasses can do without nitrogen fertilization for a long time. Hay crops of any kind including summer annual forages require a fertilizer budget and should be planned accordingly.”

To learn about extension programs in Arkansas, contact your local Cooperative Extension Service agent or visit www.uaex.uada.edu. Follow us on X and Instagram at @AR_Extension. To learn more about Division of Agriculture research, visit the Arkansas Agricultural Experiment Station website: https://aaes.uada.edu/. Follow on X at @ArkAgResearch. To learn more about the Division of Agriculture, visit https://uada.edu/. Follow us on X at @AgInArk.

Dry weather patterns leave pastures thirsty; ranchers worried

By Mary Hightower
U of A System Division of Agriculture

NORTH LITTLE ROCK, Ark. — Arkansas livestock producers may be getting a little worried as their forage and hay pastures turn thirsty and rainfall is more random and scattered.

While Arkansas saw a very wet April, the May 30 Drought Center map showed nearly 42 percent of the state as being abnormally dry.

Justin Condry, meteorologist for the National Weather Service at Little Rock, said Monday that an emerging El Niño will mean the return of a more typical summer weather pattern for Arkansas.

“We’re going to see a lot of pop-up showers in the afternoon,” he said. “It’s that kind of thing where your neighbor down the road could pick something that you may not.”

A pattern of dry weather has set in, causing ranchers concern about their hay meadows and pastures. File photos.

Condry said the summer outlook from the Climate Prediction Center covering June, July and August projects “slightly above-average temperatures and slightly above-average rainfall.”

However, Condry cautioned that the three-month outlook is generalized and that not everyone will see above-average rainfall through the summer.

Smaller hay cuttings

Cody Burkham, executive vice president of the Arkansas Cattlemen’s Association, said he hasn’t heard of anyone resorting to hay for forage yet, he reports some cuttings in north central Arkansas are a “quarter to a third below average.”

The National Agricultural Statistics Service report on Monday showed 13 percent of non-alfafa hay in poor condition, with 11 percent of pastures in poor or very poor condition.

“We are becoming very concerned about the dry conditions in Van Buren County,” Danny Griffin, county extension staff chair for the University of Arkansas System Division of Agriculture, said Monday. “Most producers who fertilized early have made an average hay crop, but many are concerned about making a second harvest or having to feed the first due to lack of rain on pastures.

“Our soils dry out quickly,” Griffin said. “The old timers used to say that ‘we are always two weeks from a drought at any time’.”

Prussic acid

The drought brings an additional grazing concern, he said.

“I have been on the phone this morning with a producer concerned about grazing sorghum-sudangrass that he planted and fertilized,” Griffin said. “It can accumulate nitrates and prussic acid in drought conditions and become toxic to grazing animals.”

In Jackson County, which includes parts of the eastern Ozarks, “Hills are drying up fast from what I saw last week,” said Matthew Davis, Jackson County extension staff chair. “Many water holes are dry and any non-diverse forage areas are struggling. The higher up on the Ozarks you go the worse it is because of the shallow soil.”

Davis also said that “grazing rotations are being impacted by lack of water in places, and non-irrigated hay ground won’t be cut anytime soon because grass isn’t growing off.”

Back to forage management basics

Maggie Justice, assistant professor and extension beef cattle specialist, said now is not the time to forget basic forage management.

Water — “Make sure your animals have access to good clean water. Make sure to monitor natural water sources more closely during drier times,” she said.

Monitor your pastures — “Be more aware of toxic plants in your pastures,” Justice said. “Cattle grazing short pastures are more likely to consume toxic plants.”

Justice also said producers shouldn’t let cattle graze too long on short pastures, since it will make it more difficult for grass to recover.

“Let the grass grow back before grazing,” she said. “Concentrate cattle in a ‘sacrifice’ area if needed. Close the gates and give your remaining forage a chance.”

“Start thinking about long-term management decisions such as animals that might need to be culled,” Justice said. “Consider culling open cows, old and low producers in the herd. This will provide more feed for the younger and more productive cows.”

“If you have to start feeding hay due to lack of forage — don’t waste the hay!” she said. “Use recommended methods for properly feeding hay such as feeders that minimize waste, unrolling hay, and limiting the time cows have access to hay each day if needed.”

Find information on prussic acid and cattle and managing cattle in drought online and at your county Cooperative Extension Service office.

To learn about extension programs in Arkansas, contact your local Cooperative Extension Service agent or visit www.uaex.uada.edu. Follow us on Twitter and Instagram at @AR_Extension. To learn more about Division of Agriculture research, visit the Arkansas Agricultural Experiment Station website: https://aaes.uada.edu/. Follow us on Twitter at @ArkAgResearch. To learn more about the Division of Agriculture, visit https://uada.edu/. Follow us on Twitter at @AgInArk.

As rainfall patterns become more extreme, pasture managers will need to become increasingly proactive

By the U of A System Division of Agriculture 

FAYETTEVILLE, Ark. — Average temperatures in Arkansas have risen about 0.5 degrees over the past two decades, according to the North Carolina Institute for Climate Studies. One result of this has been more extreme patterns of rainfall and drought. Dirk Philipp, associate professor of forage agronomy for the University of Arkansas System Division of Agriculture, said these changes in rainfall patterns typically have a variety of effects — particularly on agriculture.

DELUGED — Heavy rainfall can take a toll on pastures not equipped to manage runoff. (Image courtesy Dirk Philipp.)

Based on current climate and weather patterns, Philipp said, these weather extremes may include increased rainfall intensity and extended periods of both higher and lower rain frequency, leading to flooding and drought, respectively — and these changes in rainfall patterns typically have a variety of effects.

“For example, increased intensity means the rain has a higher impact on soil, which equates to higher erosion potential,” he said. “There’s a higher potential for runoff and dislodging soil particles.”

Philipp said changes in rainfall patterns may also lead to decreased rainwater infiltration rates, meaning the soil itself will retain less moisture and aquifers will be slower to recharge. And because evaporation rates are high in the southeastern United States, droughty periods will be relatively more severe for plants in that region than in higher latitudes where incoming solar rays are less powerful.

“Changing rainfall patterns also have biological effects,” Philipp said. “Planting times are affected, because fields may be wetter or drier than in the past during the usual planting times.”

All of this will put stress on existing forage stands and will have implications for establishing new stands as well, Philipp said. To make pastures more resilient in the long term, he has several key suggestions.

“Buffer strips in strategic locations go a long way in capturing runoff and helping to infiltrate it into the soil,” he said. “Extended riparian areas will also achieve that. Buffers around 50-100 feet wide can be grazed, as well.”

Philipp said pasture managers should be conscious of the topography of their land, and should consider reforesting areas that were likely covered in woodlands before farming.

“This doesn’t have to cover a lot of area, but if you can set aside a few acres, that will go a long way of keeping as much rainfall on your land as possible,” he said.

Strategic choices
Philipp said producers should be strategic with their choice of forages, making their lands more resilient and lowering their economic risks.

“For example, native perennial warm season grasses are drought resistant,” he said. “Plant them in areas that may get more affected by drought. Eastern gamagrass works well for wetter areas and is readily grazed by cattle. Placing cool season perennial forages, such as fescue or orchardgrass, alongside riparian zones will provide forage for spring and fall while decelerating runoff.”

Riparian zones are where land and lakes or streams meet.

Finally, Philipp said that whatever choices producers make initially, it’s important to remain flexible and realize they will need to further adapt over time. This can mean keeping more residual forage after a grazing event, avoiding prolonged stocking in late winter on cool season pastures and more.

“Calculate your forage needs for summer grazing, and plan long-term for planting more areas in warm season annual and perennial forages,” he said.

To learn about extension programs in Arkansas, contact your local Cooperative Extension Service agent or visit www.uaex.uada.edu. Follow us on Twitter and Instagram at @AR_Extension. To learn more about Division of Agriculture research, visit the Arkansas Agricultural Experiment Station website: https://aaes.uada.edu/. Follow on Twitter at @ArkAgResearch. To learn more about the Division of Agriculture, visit https://uada.edu/. Follow us on Twitter at @AgInArk.

Fall Armyworms Appearing in High Numbers in Arkansas pastures

TRUE ARMYWORM - A key characteristic of true armyworm larvae is a brown net-like pattern on the head.

Media contact: Mary Hightower          mhightower@uada.edu               501-671-2006

July 15, 2021

Fall armyworms appearing in high numbers in Arkansas pastures

By Mary Hightower
U of A System Division of Agriculture

Fast facts

• High numbers of armyworms seen

• February’s deep freeze had little impact on populations

• Cattle producers should scout in the field

 FAYETTEVILLE, Ark. — The fall armyworms surging through Arkansas pastures and lawns apparently don’t understand the concept of a killing freeze.

Like the old saw, this army travels on its stomach, and searches for tender plants to eat. The armyworms can often render a lush pasture nearly barren in a day.

“Right now, we’re seeing populations well above treatment thresholds in southern, southwestern and western Arkansas from Mena into Fort Smith and Van Buren,” said Kelly Loftin, extension entomologist for the University of Arkansas System Division of Agriculture. “We’re seeing reports in north-central regions like Cleburne County over into Greene County.”

Numbers have been increasing each week for the last 2 1/2-3 weeks. Fall armyworm catches have been highest in the following:

• heavily fertilized Bermudagrass hay fields

• irrigated Bermudagrass hay fields

• hay fields where Signalgrass is present

• newly planted bermudagrass and crabgrass fields

“It’s a pretty intense year,” he said. “It’s a shocker.”

The deep freeze that took over much of Arkansas, Texas and other parts of the South back in February should’ve put the kibosh on fall armyworms.

“Armyworms overwinter as adults in south Texas,” Loftin said. “If we look at the temperatures we had in February, we would’ve expected more winter mortality.”

"Because of the extended rains during the spring, many ranchers had both quantity and quality issues in their first cutting of hay, making it all the more imperative to protect what’s left in meadows and pastures, for future grazing or cutting,” he said.

Scout pastures

John Jennings, professor and extension forage specialist for the Division of Agriculture, said lots of infestations are being reported.

“Often the armyworm moths are attracted to the most tender growing forage, so new growth on recently cut hay fields, well-managed pastures and newly planted summer forages like millet, sorghum/sudan, and crabgrass are at greatest risk,” he said.

Damage from small armyworms often shows up as light-colored grass tips similar to frost or as small patches of green tissue missing from the leaf surface called windowpane feeding. Damage from larger worms is more obvious with leaves and young stems being eaten.

“Producers should scout all fields closely with in-field observations and not from the pickup windshield,” Jennings said.

Find additional information at the extension armyworm page; https://www.uaex.edu/farm-ranch/pest-management/insect/armyworms.aspx

Download the fact sheets: “Managing Armyworms in Pastures and Fields,” https://www.uaex.edu/publications/pdf/FSA-7083.pdf and “Fall Armyworm Recognition and Management” at https://bit.ly/3wFGKen.

To learn about extension programs in Arkansas, contact your local Cooperative Extension Service agent or visit www.uaex.uada.edu. Follow us on Twitter and Instagram at @AR_Extension. To learn more about Division of Agriculture research, visit the Arkansas Agricultural Experiment Station website: https://aaes.uark.edu. Follow on Twitter at @ArkAgResearch. To learn more about the Division of Agriculture, visit https://uada.edu/. Follow us on Twitter at @AgInArk.

About the Division of Agriculture

The University of Arkansas System Division of Agriculture’s mission is to strengthen agriculture, communities, and families by connecting trusted research to the adoption of best practices. Through the Agricultural Experiment Station and the Cooperative Extension Service, the Division of Agriculture conducts research and extension work within the nation’s historic land grant education system.

The Division of Agriculture is one of 20 entities within the University of Arkansas System. It has offices in all 75 counties in Arkansas and faculty on five system campuses.

The University of Arkansas System Division of Agriculture offers all its Extension and Research programs and services without regard to race, color, sex, gender identity, sexual orientation, national origin, religion, age, disability, marital or veteran status, genetic information, or any other legally protected status, and is an Affirmative Action/Equal Opportunity Employer.