Ryegrass is a high-yielding, high-quality winter forage that is “phenomenally inexpensive” to produce. So why are only a handful of California dairy operations raising it?
“It's received a bad reputation over the years,” reports John Kennedy, a dairy nutrition and forage consultant based in Lodi, CA.
“People were taking just one cutting, and getting only heifer-quality forage,” explains Kennedy. “But we're showing that, if you manage ryegrass correctly, you can get two and sometimes three cuttings of haylage-quality forage.”
What's more, ryegrass thrives in the cool, wet soils of a Northern California winter and might be an even better fit in the southern San Joaquin Valley where growers have more control over soil and water conditions, says Kennedy.
A final advantage of ryegrass is that it's very effective at taking up whatever nutrients are available in the soil. That's especially important in California, where dairies are under strict rules governing manure disposal, notes Mick Canevari, extension agronomist for San Joaquin County.
For the past two years, Canevari has conducted the largest ryegrass field trials in California. He's found that a typical yield from a high-quality tetraploid ryegrass is around 7,000 lbs of dry matter. On a fresh weight basis, two cuttings will yield around 16 tons, notes Kennedy.
Canevari didn't test for protein, ADF or TDN. Kennedy says he averages 15% crude protein and 60% TDN at 90% dry matter.
“It's being fed to milk cows, not just replacement heifers,” says Kennedy. “It's a very palatable feed and can take the place of alfalfa haylage in the ration.”
The key is to harvest it at the right time. Kennedy recommends cutting at a height of 15", or what he calls late-vegetative stage. The majority of the forage should be grass leaves, not stems and certainly not seedheads.
By cutting at the right time, growers can expect “two 8-ton cuttings vs. one 13-ton cutting, and an increase in quality of three to four units of TDN and five units of protein,” says Kennedy.
With its ability to thrive in cool, wet soils, ryegrass would seem best adapted to northern California. And it is. But Kennedy believes its greatest potential is in the southern San Joaquin Valley.
“There are some very large dairies in the Tulare and Hanford areas that have a lot of manure water they'd like to dispose of in the winter,” reports Kennedy. “Ryegrass is a highly palatable forage that yields well. And the ability of producers in the south to irrigate makes a second cutting easily attainable, plus the lower rainfall and humidity allow better timing and wilting of the first cutting.
“The critical targets of less than 75% moisture and less than 4.3 pH are easier to achieve in this area,” notes Kennedy. “And the second cut taken four to five weeks later allows growers adequate time to plant early summer crops.”
Born and raised in Ireland, he brings his native land's ryegrass pasture experience to California. He says the keys to raising a high-quality ryegrass are seedbed preparation, seed selection, an eye on nutrients, and harvest scheduling.
Ryegrass is suited to most soils, says Canevari, and should be planted a half-inch deep into a seedbed that is fine to semi-cloddy at a rate of 30-40 lbs per acre. The seed should be a high-quality tetraploid variety from Oregon, which costs around 30¢/lb.
“So your seed is phenomenally inexpensive for what you're getting,” says Kennedy.
Ryegrass will take up as much nitrogen as is available, so growers should be careful not to overapply manure water on the ground and should test the forage for nitrates after it's harvested. If it's too high in nitrates, it needs to be mixed with other roughage when fed.