The Forage Seeding Gamble

Establishing forage is a lot like playing poker, according to Marvin Hall. If you plan ahead and count your cards, you've increased your chances of winning.

“There's a certain risk you take in forage establishment; sometimes you win and sometimes you lose,” says the Extension forage specialist from Penn State University.

“Lack of planning is planning for failure — plan for a successful forage establishment at least a year in advance,” he adds. “Going out the day before to the local feed mill, buying whatever seed is available and planting it is a recipe for disaster. The expense is too much to be gambling like that.”

First, consider your soil's fertility and which forage species work best for your situation. Also work to control weeds in the previous crop.

“Those of you in rotation, going from corn back into forages, you've got this down. Those of you who aren't doing that as frequently need to think about it a little bit.

“If you want to plant alfalfa and your soil is at 5.5 or 6 pH, that doesn't fit very well. You either need to move the pH up or change the selection of species.”

A grower may want to choose among species that produce early in spring or keep producing during summer slump or stockpile well into fall. Try matching species to environmental limitations, such as shallow or wet soils, he says.

“Maybe you have no ability to make silage. Red clover may not be your best bet because it's difficult to get made into hay. Think about the options and then identify the species that fit.”

Six months before planting, add needed lime or fertilizer and again be proactive in solving weed problems. Then research varieties of the species you've decided to plant. “Talk to your seed dealers and consult university evaluation trials. How did that variety perform in your state?”

Several other factors that can affect whether you get a good forage stand are as follows:

Seed quality

To increase your odds, especially if you've bought seed early or can't plant it right away, store it where temperature and humidity will total 100°F or less. “If you've got a temperature of 85 and humidity of 60, that's not good. The enzymatic activity in seeds is still very active, and you're degenerating or using up some of the carbohydrates and weakening the seed. Put it where it's cool and low in humidity.”

Buy quality seed and compare old and new varieties for insect and disease resistance and winterhardiness. University and seed company data are available from several sources.

Seeding rates

Hall lists species seeded at 1, 2, 5 or 10 lbs/acre to compare the number of plants per square foot that could potentially emerge (see above table).

“If you look at alfalfa, 1 lb/acre gives you 5 (plants/sq ft), 2 lbs give you 10, 5 lbs give you 25. Most of us would say, ‘Boy, if we had 25 plants per square foot, that would be a successful establishment. So all we need to do is seed at 5 lbs/acre.’”

Most university specialists, however, recommend several times as much seed as would be theoretically needed for successful establishment, he says.

“That would take care of a lot of sins we may have — the soil may not be perfect, competition, insects — all sorts of things like that.”

Research on alfalfa seeded at 9, 15 and 24 lbs/acre appears to support university recommendations. Initially, there was a huge difference in the number of plants that emerged, Hall says.

Yet within 12 months, stands from higher seeding rates were fairly close in comparison to stands seeded at lower rates.

“So seeding at higher-than-recommended rates initially gives you more plants, but, eventually, they're going to compete and narrow down to about the same seeding rate.”

Time of planting

Spring seeding gets the crop in ahead of weeds and allows forages to establish before being exposed to summer heat and drought. “Certainly late summer is an ideal time for planting, but that timing is very crucial,” he warns. By then soil is drying, which means less compaction and fewer weeds. Late-summer planting also means seedlings can establish in cooler fall weather.

In a Pennsylvania study, legumes and grasses were seeded Aug. 1, Sept. 1 and Oct. 1.

“We got stands that, the next year, took a hit on yield as we delayed our planting date.” Alfalfa yields decreased by 120 lbs/acre for each day after Aug. 1 that planting was delayed. Red clover dropped by 80 lbs/acre/day; birdsfoot trefoil, 60 lbs; and reed canarygrass, 100 lbs/acre/day starting toward the end of August.

“Grasses do better if we delay planting until about Sept. 1.” The reason: Grass growth from early planted seedlings shades and kills new tillers.

Planting depth

“This is the No. 1 cause of failure,” Hall says. “We tend to put our seeds way too deep. Little seeds shouldn't be more than two times their diameter in depth below the soil surface.”

A study on forage seed planted at ¼", ½", 1" and 1½" depths and deeper showed fairly high germination and emergence at ¼" and substantially less at ½". At an inch, germination and emergence equalled 50% and it got worse from there, he says.

“So getting it in at that shallow depth is real important. I use two rules of thumb. When I have a field ready to plant, I walk over it. If the heel of my work shoe sinks in more than ½”, it's too loose and fluffy, and I'd probably seed too deep. Once I start seeding, I go behind the drill; if I don't see about 10% of the seeds on the soil surface, I'm putting them too deep.”

Seed-to-soil contact

“That's the No. 2 cause of failure. Those seeds have to absorb more than 100% of their own weight in water before germination kicks in. Seeds get that water from the soil — you need to have good seed-soil contact so there's a lot of area for water to move into the seed quickly.”

Soil clods inhibit water movement. “It's important to have a very fine seedbed. With corn and other crops, it can be cloddy, but for forage, you have to have a lot of fine particles surrounding the seed.”

Inoculate legumes

“Science says that if you had alfalfa or another legume in the field within the past three to five years, you probably wouldn't need to inoculate. However, the new lines of inoculants out there are far superior. It's fairly cheap insurance to make sure you have the proper inoculant and the right amount of it.”

Match seeding method with soil preparation

“Don't attempt to no-till seed with a regular drill. Use the right implement to get the job done.”

Minimize weed competition

Do what you can to give the forage plants the best chance of getting the sunlight and nutrients they need, Hall says.