It was in his high school agriculture class that Bill Miller first learned the benefits nitrogen-fixing legumes provide when they're incorporated into grass pastures. Those not-so-long-ago lessons gained by this Izard County, AR, stocker-calf operator are today paying off in his grazing rotations.
Warm-season perennial grasses have been the mainstay for pasture grazing systems throughout the Southeast. Producers have shied from legumes as they are generally not well adapted to the region's soils and climates. Today though, some new varieties of cool-season legumes — particularly types of white clovers — have improved legumes' lot in life and are gaining increased respect and attention.
Miller manages intensive grazing sysArkansas, as well as farms he and his father lease. He says it's always a challenge to keep grazing costs to a bare minimum while maintaining optimum productivity.
The first step Miller took in increasing grazing efficiency was to improve his farms' poor soil fertility. He used chicken litter from the four poultry houses his dad built in the late 1980s.
The second step was to find forages that thrived in the more fertile soils.
“We studied nitrogen fixation and legumes in school,” Miller explains. “I remembered that clovers specifically were good for the soil and could work well in pasture forage mixes.”
The “new” white clovers
A few years ago, a bell went off for Miller — he could grow this type of clover in his own pastures.
Miller began experimenting with the clovers at hand — Regal ladino clover and arrowleaf white clover. The Regal clover he planted in 1990 lasted only two growing seasons. The arrowleaf clover planted that same year lasted until 2003.
But even the arrowleaf never really lived up to Miller's expectations. It became clear to Miller that his legume management skills, as well as the clover varieties he was using, needed improvement.
His dedication to clovers paid off when he seeded his first stands of Durana (2002) and Patriot (2003) white clovers. Concur-rently, he applied what he'd learned about soil testing, timing of fertilizer application and grazing management as interrelated components of successful legume establishment and stand survival.
While the jury is still out regarding the longevity of Miller's new clover stands, he's already convinced these varieties are a cut above the varieties of the past.
“We've learned the new varieties of clover on the market allow for some errors and are much easier to establish and maintain,” Miller says. “I've been impressed with the vigorous growth of these clovers — to the point where I think we could abuse them even more than we do — and still have good stands.”
Gerald Evers, Texas A&M University forage agronomist at Overton, is a firm believer in adding cool-season legumes to warm-season perennial grass pastures.
“The cool-season legumes can help overcome some of the limitations of the warm-season grasses, while providing additional benefits,” Evers says. The main “limitation” of warm-season perennial grasses is their relatively low nutritive value and high nitrogen requirements, he adds.
“When cool-season legumes are over-seeded on warm-season perennial grasses, grazing can begin six to eight weeks earlier, thereby reducing hay and supplements costs associated with winter grazing,” Evers says. “The nutritive value of legumes is higher than the grasses because of more digestible and higher protein — and they provide more nutrients — especially calcium, phosphorus and magnesium.”
With the proper inoculation by rhizobia bacteria, the perennial legumes can fix as much as 100 lbs. of nitrogen/acre, he adds.
Requiring more management
In spite of all the benefits of forage legumes, Evers says many Southeast cattle producers are reluctant to use the legumes because, as Miller discovered, they require more management than grasses.
Lloyd Byrd of Scott County in east-central Arkansas is another cattleman who has learned how to grow clover. Enrolled in the Arkansas Beef Improvement program since 1998, Byrd has worked to reduce grazing costs through better soil fertility and new plant materials.
Each year he tries to cover about one-third of his farm with broiler litter from nearby poultry houses. He's also sown arrowleaf and red clovers — and of late, white clover — into his pastures. His seeding methods are less than high-tech.
“I seed the clovers with a hand-crank yard seeder while sitting on the pickup tailgate as my wife drives up and down the pastures,” he says. He lets the cattle's hoof action incorporate the seed into the soil — then he lets it spread from there.
“We've not sown clover into all of the fields, but all the fields have clover,” he says. By rotational grazing — and feeding the clover-grass hay during winter in selected pastures — Byrd's been able to take advantage of the clovers' aggressiveness and leverage the money he's spent for seed.
“We also have an ongoing weed control program,” he adds. “Buttercups are the biggest problem — we spray with low rates of 2,4-D in early March so we can get the weeds without killing the clover.”
Another management practice of Byrd's is to “Brush Hog” behind the cattle as they rotate from the pastures.
“During late summer when the forages aren't growing, I graze them hard and then follow them with a Brush Hog,” he explains. “This knocks down the weeds and coarse grasses the cattle don't graze, and it opens the forage canopy so the clovers can grow when it rains.”
Advice for the clover novice
Miller and Byrd are among the many Southeast producers experiencing the complexities of growing clovers in their pastures. And Evers has some advice for others who might be legume novices.
Spend time visiting with other producers in your area who are successful at growing legumes.
Learn which legumes are best adapted to your environment. Take soil samples and pay close attention to fertility management.
If overseeding, scruff the sod lightly to reduce competition and provide some loose soil for a good seedbed.
If planting a legume into grasses, limit nitrogen fertilization to late fall and winter.
Utilize spring legume pastures with beef cows that calve in January-February.
“And, be patient — there's no substitute for experience,” Evers concludes. “The first year will be a learning experience, but your legume pastures will improve as your management improves.”
Growing cool-season legumes
Gerald Evers, Texas A&M University forage agronomist at Overton, offers some tips for Southeast producers wanting to try cool-season legumes in their pasture mixes.
- Select the right legume
Forage legumes adapted to the Southeast differ in their growth habits, growing seasons, cold tolerance and adaptability to soils and climates. Local Natural Resources Conservation Service offices can help in identifying the soils on your farm.
Varieties developed locally are usually more adapted and productive than those of other regions. Plant only a small acreage of a new variety before making large investments in seed, land preparation and labor.
- Seed inoculation is important
Most legume species have specific rhizobia strains that work to maximize nitrogen fixation. The inoculant should be ordered to arrive as near to planting as possible. It should contain a coating or “sticker” to hold the inoculant to the seed. Follow label instructions on how to mix the inoculant and keep it fresh and active.
- Managing legume pastures
Try to maintain a balance between grazing the cool-season legumes and the warm-season grasses. A major tool in doing this is rate and time of nitrogen fertilizer application. A general consensus is that a minimum of ⅓ legume is necessary to make a significant contribution of forage and nitrogen.
Nitrogen fertilizer is usually needed in late fall to stimulate grass production for grazing. No nitrogen should be applied after March 1 if the legume accounts for about half of the available forage at that time, as spring is the main legume-growth period.
- Bloat considerations
Management against bloat centers around not allowing young succulent legumes to constitute the majority of the animal's diet. Take care when first turning cattle out onto legume or legume-grass pastures in the spring. A transition period of one to two weeks when livestock have access to both hay and legume pasture is helpful in reducing bloat.
Grazing can be limited with the use of portable power fencing systems to achieve “strip grazing” — also an excellent way to maximize returns from grazing mixed forages.
Various brands and types of anti-foaming agents can also be fed. Consensus is that the benefits of grazing legumes outweigh the risk of bloat.
— Clint Peck