Cattle ranchers today don't really like to be called farmers. And when the time comes to plant a piece of ground to a stand of hay or tame pasture, most wish they'd paid a little better attention to granddad's farming skills.
With attention to a few basic agronomic principles, though, most ranchers can come away with a decent stand just about every time. Beyond selection of the right forage cultivar, proper site preparation and knowledge of some basic seeding principles are among the first steps to success.
Regardless of the seeding date, method or region, there are several important agronomic principles to remember when attempting to establish forage crops.
Seedbed condition is critical
“Seeding depth and seed-to-soil contact are critical,” says Marvin Hall, Penn State University associate professor of agronomy. “A general rule of thumb is seeds shouldn't be placed deeper than five times their diameter.”
For most forage crops, seeding depth shouldn't exceed ⅜ in. Deeper seedings will drastically reduce the number of seedlings that will establish.
Dennis Cash, Montana State University (MSU) Extension forage specialist, says the ideal seedbed should be firm, uniform and mellow.
“Two critical requirements for good stand establishment are a firm, clean seedbed that's relatively free of residue, and a smooth, uniform surface,” Cash says. “Packing during seeding and afterwards will yield good soil contact with the seed.” This is extremely important for good germination and early vigorous seedling growth.
Firm seedbeds also reduce the possibility of planting too deep, and firm seedbeds hold the moisture closer to the soil surface.
For alfalfa stands, Paul Dixon, MSU Extension agent for Yellowstone County, says to pack the seedbed firm enough so that a boot print does not make an indentation of more than ¼ in.
“Seedings following another crop, such as corn or small grain, can be successful in seedbeds prepared by disking and harrowing,” Dixon adds. “This requires less time than plowing, but may not rid the seedbed of undesirable materials such as weed seeds, diseased plant parts or herbicide residues from the previous crop.”
Hall says successful forage seedings don't have to be rocket science or involve high-tech machinery.
“Successful stands have been made with many types of seeders,” he explains. “The method of seeding equipment isn't as important as achieving proper seeding depth and good seed-to-soil contact.”
Most agronomists, including Hall, say producers shouldn't attempt to seed alfalfa back into an alfalfa field within one year from when the old alfalfa was killed. They say established alfalfa plants produce a chemical toxic to alfalfa seedlings.
Rotating out of alfalfa for a minimum of one year will allow the chemical to decompose. In addition, rotating to another crop will help reduce alfalfa disease, rodents, weeds and insect pests.
When an old alfalfa stand is terminated, Cash recommends rotation to an alternative crop for two years before returning to alfalfa. He says cereal forages, such as hay barley or a winter cereal (wheat, triticale) forage, are very useful to ranchers in this two-year interval.
Cash says that, while it's generally accepted that perennial pastures are the least expensive feed sources for the beef-cow herd, the various types of annual forage systems can fill a void at specific points in the livestock enterprise. The motivation for novel pasture systems include:
Conventional pasture systems, while low cost, can't always keep up with the demands of cows, calves or stocker cattle, all of which are gaining in size and weight.
It's less expensive to over-winter beef cows conventionally if they enter the winter feeding period in good body condition.
It's cheapest to feed some classes of livestock (e.g., beef cattle) on pasture than in dry lots.
Companion crop or not?
Contrary to popular belief and long-established customs, better stands and yields are generally obtained when most forages, including alfalfa, are seeded without a companion or nurse crop. Probably the most significant reason for use of a companion crop is to help establish the stand, i.e., reduce erosion, minimize weeds, maintain high humidity and reduce wind at seedling height.
However, Cash and Dixon say cereal grain grown with alfalfa competes with alfalfa seedlings for light, water and nutrients. Research has shown this type of competition reduces yields by 20-35%, Cash says. The following can minimize the competitive effects if cash-flow needs require a grain crop during establishment:
Seed cereal grains at a depth of 2 in., in 18- to 24-in. rows.
Repack the seedbed.
Overseed alfalfa ¼-in. deep after seeding and packing grain crops.
If under irrigation, keep the alfalfa root zone moist during the growing season and irrigate immediately after the grain is harvested.
Harvest the companion crop early for silage, hay or high-moisture grain to allow the alfalfa seedlings more time to grow and build up carbohydrate reserves in the root system.
“If you must plant a cover crop, oats or barley seeded at 30-40 lbs./acre ahead of seeding alfalfa should be used,” Dixon says. “Then it's best to harvest the grain crop for hay or forage rather than for grain; harvest the crop when it reaches the soft dough stage.”
Pure stands or not?
Pure stands of alfalfa usually produce the highest protein yield and often the highest tonnage on soils well suited for alfalfa. Pure stands produce an excellent cash crop, but for most cow-calf operations, a grass/alfalfa mix is more resilient and produces adequate tonnage and quality.
“Grasses are sown with alfalfa for a number of different reasons,” Cash says. “Grass fills in gaps in alfalfa stands caused by poor alfalfa establishment or winter-killing.”
Grasses also reduce weed invasion and soil erosion. If alfalfa is grazed, bloat is less likely to occur when two-thirds or more of the stand is grass. In addition, alfalfa/grass mixtures cure more rapidly and ensile more easily than pure alfalfa.
“However, the most grass yield is at first cutting, so there's little advantage of grass at later harvests,” Dixon suggests. “Many herbicides used for weed control in alfalfa injure or kill grasses, so having a forage grass in the stand restricts the herbicides that can be used.”
Some current research indicates that alternate-row seedings of alfalfa with a grass are beneficial during establishment vs. a seed mix in the same row.
Renovating thin stands
Most research and producers agree that interseeding alfalfa or other forages into thin stands is rarely successful. Thickening an existing alfalfa stand is often unsuccessful because of soil conditions, age of stand, moisture and temperature conditions, disease, autotoxicity and competition from weeds or older established plants.
“When you add this all up, the deck is obviously stacked against a successful interseeding,” Cash explains. “To increase production, consider harrowing the thin stand and drilling an annual crop of hay barley or oats, with the intention of replacing the alfalfa stand the following year.”
Hall adds that response of forage seedings to starter fertilizers (small amounts of fertilizer placed near seeds at the time of seeding) has been inconsistent.
“Starter fertilizers are generally thought to be beneficial only under adverse conditions for seedling development, such as wet and cold soils, soils with low fertility or soils with poor physical properties,” he says. If soil nutrient levels are optimum to high at the time of seeding, then fertilization generally should not be a concern during forage establishment.
Because of high costs, seeding forage crops is considered to be a “high stakes” farming operation for any producer. While the days of spreading some seeds on the ground and hoping for nature to cooperate are past, Hall says forage producers can minimize risk as much as possible by following a few of the basics to ensure successful forage crop establishment.
Clint Peck is a former BEEF Senior Editor based in Billings, MT.