More and more livestock producers are looking at crabgrass, not as a weed, but as a high-quality summer hay and pasture alternative. The sturdy annual grass is gaining popularity because it can be grown alone or as a productive partner for a legume or almost any number of other grasses.
Crabgrass can be used in warm-season annual mixes — with sudangrass, pearl millet, foxtail millet, cowpeas or soybeans — and even with perennials such as bermudagrass and alfalfa, according to trials at the Noble Foundation, Ardmore, OK.
“It can also be planted after wheat or other winter annual by drilling it into the stubble. It's a very flexible forage,” says R.L. Dalrymple. The forage agronomist helped develop crabgrass varieties while at the Noble Foundation. He and his family now own Elstel Farm & Seeds, Ardmore, which sells crabgrass seed.
“It can grow in areas with a minimum of 22-24” of annual rainfall but does better with more moisture. In areas drier than that, such as to the west of Oklahoma, it needs irrigation,” Dalrymple says.
The grass's higher moisture content can be a limitation when making hay, some researchers say.
“If you sell bermudagrass hay to horse owners, you don't want crabgrass around,” says Wayne Coblentz, U.S. Dairy Forage Research Center dairy scientist. Crabgrass dries more slowly than bermudagrass and can spoil. “Horse folks are pretty finicky, and if they see crabgrass in with bermudagrass, they're afraid it's moldy.”
Yet crabgrass is higher in nutritional value than other warm-season grasses, including bermudagrass, says Coblentz, who, while at the University of Arkansas, took part in research examining crabgrass's potential as a summer slump grazing crop.
“If you want something that is perhaps a little less fibrous that will clear out of the rumen more quickly, crabgrass does that,” he says. Arkansas research showed that crabgrass's neutral detergent fiber (NDF) stayed relatively constant during July and August — 55-62%. Crabgrass broke down in the rumen 44% faster than bermudagrass.
Its crude protein content ranges from over 20% in early season growth to 12% in late August, Noble Foundation research shows. “But crude protein content is mostly dependent on nitrogen supply,” says Dalrymple.
The grass is well-adapted to the southern 25 states — from central Nebraska to Texas and to the East Coast, Dalrymple says. “But growers from as far north as Iowa, southern Indiana, Ohio and Pennsylvania have told me it has done well for them.”
Crabgrass can work well in rotation with winter annual crops in Alabama, says Don Ball, Auburn University extension forage specialist.
“It is a wonderful forage crop that fills voids. Where it has significant potential, here in my world in the Deep South, is in fields dedicated to growing winter annuals: some combination of cereal rye, wheat and oats; annual ryegrass; and annual legumes such as crimson and ball clover.”
Winter annuals planted in September usually peter out by May, so crabgrass can pick up where they leave off. The ideal time to initially establish crabgrass: March or April. Once a good crabgrass stand is growing, it can be managed so it comes back year after year. The stand needs to be allowed to make seed, be fertilized each spring and be on soil that gets tilled yearly.
“This can result in a nice alternative cool-season, warm-season pasture of very good quality year after year,” Ball adds.
When planted as a single crop (3- to 6-lb/acre seeding rate) with good growing conditions and adequate moisture, crabgrass can yield 4,000-8,000 lbs of dry matter per acre. The Red River variety, developed by Dalrymple and other Noble Foundation researchers in the 1970s, has yielded 8,000-12,000 lbs of dry matter per acre under optimum growing conditions in research plots.
Red River crabgrass stays green the full season, is a prolific seed producer and has no serious disease or insect problems, he notes.
“If you want the crop to reseed, quit grazing it three to four weeks before a killing frost to allow seed to set. The following spring … go over ground with a disk or harrow in late April or early May for better seedling growth and total production.”
In spring, crabgrass seed can be broadcast, then lightly harrowed, or planted with a no-till drill. But the seed is small, so shouldn't be planted deeper than ¼”, he says.
Like all grasses, crabgrass likes nitrogen. “To get a medium-quality crop, apply a minimum of 50-60 lbs/acre of nitrogen. But ideally, in a dryland situation, a split application of 50 lbs of nitrogen in the spring and 50 lbs in mid-summer will help you get maximum yields. A good rule of thumb is that the crop needs 1-2 lbs of nitrogen per growing day.”
A new variety developed by Dalrymple, Quick-N-Big, is taller and faster-growing than Red River. “It sprouts and grows quicker, reaching 12-14" at the same time Red River is about 3-4" tall,” he says. “Beyond that, most of the quality characteristics are similar to the Red River variety.”
Many growers who have tried the new variety, which is available in limited quantities its first few years, have a time staying ahead of it, he says. “If you cut it in the 18-24" height range, you'll get good hay.”
The same holds true for grazing, he says. “You need to be ready to start grazing it when it's between 4" and 8" tall, and that will be sooner than other crabgrass varieties.”
The average full height of Quick-N-Big is 43", but Dalrymple has seen it as tall as 56" under ideal conditions. “It does tend to get stringy when it's that tall, since the nodes are farther apart on the stems.”
Quick-N-Big was certified in 2008, is available through Elstel Farm & Seeds and costs $6-9/lb for new-crop pure live seed and $6.50-10/lb for aged seed. Red River certified seed typically sells for $5.50-7/lb.
For more on Elstel Farm & Seeds, go to www.redrivercrabgrass.com.