Spring is a time of new beginnings on the farm — a time when winter planning is put into action. But it is also a time of risk, especially for planting alfalfa.
“Several county agents and I have received quite a few calls and questions about alfalfa in the past month,” said Calvin Trostle, Texas, Cooperative Extension agronomist based in Lubbock. “Even though alfalfa is a good crop when you want to branch out and diversify your cotton or grain operation, we do not recommend seeding it in spring. The best time to plant alfalfa in west Texas, and especially on the High Plains, is in the fall.”
“The statewide recommended planting date is Aug. 20 to Oct. 1. Here on the High Plains, the best window for planting alfalfa is from early to mid-September. That puts us past the worst of our summer heat, and we can still get at least six weeks of growth and development before the first killing frost.”
Spring-planted alfalfa is a risky business at best, he says, because the root systems and crowns of spring-seeded plants may develop poorly in response to longer day length. Weed and insect problems also tend to be more severe, and yield potential is lower.
“First-year yields of spring-planted alfalfa are often 50 percent less than comparable yields from a fall seeding. In many cases, we'll be lucky to get more than two cuttings from a spring-seeded crop,” Trostle said.
“That compares to at least four cuttings from a well-managed, fall-seeded crop. Oklahoma State University research trials suggest spring-planted alfalfa yields never quite catch up to fall-seeded alfalfa yields in subsequent years of production.”
Trostle said growers who are going to invest $2 to $3 per pound for alfalfa seed shouldn't gamble on spring seeding — especially when the cost of seed alone approaches $50 to $75 per acre.
“We can't afford to cut corners if we want a good, productive stand of alfalfa. The crop should have a productive life of at least four years, so why take a chance on getting a low-performance crop from spring seeding?
“It's a high-cost risk even if we hedge our bets by spring seeding alfalfa into a good small grains cover crop.
“Some recommendations from Leonard Lauriault, New Mexico State University forage agronomist in Tucumcari, gives us a good handle on how to manage a fall-seeded alfalfa crop here in West Texas.”
Those recommendations include:
Select a locally adapted variety with disease and insect resistance.
Pull a soil test and fertilize accordingly to maximize growth each year.
Prepare a firm seedbed to ensure good seed-to-soil contact.
Use a seeding rate of 15 to 20 pounds per acre, and a planting depth of zero to one-half inch. (Trostle recommends a minimum 20-pound seeding rate.) Higher seeding rates do not ensure better stands or higher long-term yields.
Irrigate to prevent soil crusting and to promote good emergence.
Make cuttings between bud and first flower to maximize yield and forage quality.
Protect the crop from weeds and insects with a pest management program.
Give the crop a seven-week rest between the last two fall cuttings, to help ensure a long stand life.
“When it comes to watering, we believe it will take at least six to seven inches of rainfall or water under sprinkler irrigation to produce one ton of forage or hay here on the Texas South Plains. As you go further north in the Panhandle, the irrigation/water requirement may be about an inch less,” Trostle said.
“Extension's Texas Alfalfa Production guide pegs irrigation/water use at about 10 inches per ton, but that is for production farther south using row watering.
“That guide is available through Extension county offices, or you can download it from the Internet at http://texaserc.tamu.edu. The guide contains a formula on page five that can help producers pin down their upper acreage limit when they try to fit field size to their irrigation capacity. The same formula lists maximum evapotranspiration (ET) from alfalfa at 0.35 inch per day. That is probably a realistic average for June through August on the High Plains, but it will be much higher on hot, windy days.”