Seed Placed Starter Delivers in Winter Wheat

Ontario research shows an average of 7.5 bushels more wheat. Add in improved winter survival and a more uniform stand and you have an agronomic no-brainer.

Stooped over a seed trench late at night, squinting through the beam of a flashlight at dark grey soil, Alan McCallum still doesn’t doubt how worthwhile starter fertilizer is for a wheat crop.

In fact, if McCallum figures if he doesn’t see grey fertilizer in the seed trench, it’s worth putting the brakes on winter wheat seeding no matter how ominous the forecast or how late in the fall it is. In his mind, starter fertilizer is that important. He is a crop consultant in Elgin County and recommends to all his clients that they use starter fertilizer, including when he helps his brothers plant winter wheat.

“One of the main problems we’ve had with starter fertilizer also ends up being the best way to prove to ourselves that it’s worthwhile,” says McCallum. “When the primary fertilizer hose on the air drill gets plugged, it’s not hard to tell where it happened come spring. You see a marked difference in the maturity of the wheat.”

Some of the plot work McCallum and his brothers did a few years ago showed a yield response of up to 19 bu./ac. on lower testing clay soils. On old pasture ground, where you tend to have lower background phosphorus levels, the yield response can be even greater.

That’s what Peter Johnson, cereals specialist with OMAFRA, sees too. “Seed-placed starter fertilizer, on average, can produce a 7.5 bushel yield increase,” he says.

Johnson always tries to put in a test strip with no starter in his trials. In the spring of 2011, winter wheat planted the previous fall with no starter fertilizer would have been ripped up because of poor winter survival. “In the rest of the field, the stand with starter fertilizer was essentially perfect,” he says. “Starter fertilizer increases winter survival and crop uniformity.”

With $7/bu wheat, the payback on $800/tonne phosphorus is obvious, says Johnson. The economics of adding starter is better in this environment than when phosphorus was $600 and wheat was $4/bu. 

Liquid versus MAP 

Johnson has done experiments with liquid fertilizer. He put down boards over rows of wheat and found that if you’re only applying 2.5 gallons/acre of liquid fertilizer, you might as well save your money. “The problem is that with that low a rate you’re getting a drop here and drop there so there’s a whole bunch of seed going down with no phosphorus,” says Johnson. “Maybe if we had more even distribution it would make a difference.

When we go from 5 gallons to 10, well 5 gallons is okay and 10 gallons does a pretty nice job.”

Liquid fertilizer is good and convenient, but expensive. If you’re set up for liquid starter fertilizer already, Johnson suggests trying 5 gallons of fertilizer with 5 gallons of water to reduce costs but maintain good distribution.

Adding sulfur and zinc to phosphorus in a starter fertilizer, such as through the MESZ product, doesn’t do much on winter wheat, says Johnson. He says sulfur appears to disappear over the winter.

If you’re set up for dry starter fertilizer delivery, Johnson says 50lbs of MAP is good, but 100lbs, of course, is better. When looking at rates it depends on your equipment capability.

McCallum and his brothers have been using the same mix for years – basically 9-43-10 blend comprised of 83% MAP and 17% potash. “There’s nothing magic about that at all, but we feel a little potash in the trench isn’t a bad idea,” he says, “It’s a source of potassium early on and a little bit of that chloride may give us some disease protection. The downside to including potash in the blend is that it’s a salt and a bit more corrosive on our equipment.”

Johnson says that based on just two years of data, potash on wheat is less important than on corn and soybeans. But he says don’t drop potash to zero.

Equipment Challenges

Starter pays. No question. But anyone who hasn’t invested in an air cart in the past 10 years will tell you feeding wheat at planting isn’t the easiest job.

“When they first built seed drills every drill had a fertilizer box on it,” says Johnson. “We realized how efficient it was to put starter with seed rather than broadcasting it all over the place.”

But by 1998, less than 10% of growers had fertilizer capability on the drill. “Everybody wanted big and fast and convenient,” says Johnson. “The ability to do it fast mattered more than the ability to do it right.”

Growers also got away from starter because it’s hard on equipment. For all kinds of reasons, an air cart is the simple answer. Newer air carts have a split box with a compartment for seed and another for fertilizer. Most are made of plastic now, which doesn’t rust. Air carts allow blending of fertilizer at a reasonable amount – 100 pounds of MAP with wheat seed for excellent response.

If you don’t have an air cart and just a single box drill, you can blend the phosphorus and seed while augering everything into the box. It’s harder to be accurate with rates using this method.

“It works but it’s a pain,” says Johnson. “The easy answer is buy yourself an air unit and mount it on the drill. It costs a little more than liquid kit but you’ll pay less for fertilizer and it will last just as long. It’s a simple way to get back in the game and not rust the drill out.”

McCallum and his brothers run dry starter fertilizer through a John Deere 1850 air seeder with a commodity cart towed behind. “It’s very standard, run of the mill equipment,” says McCallum. “It’s plumbed so that material from the front tank and back tank can go into the same slot.”

An air cart is used to allow for seed placed fertilizer when planting winter wheat

The most common frustration running starter fertilizer through an air cart is plugged tubes. “Fertilizer quality is very important,” says McCallum. “The less fines the better. When we get into metering rolls, a little chunk of fertilizer fines can wreak havoc.”

Blockage monitors on an air seeder will howl if one tube is completely blocked. But with McCallum’s setup, because it’s just a blockage sensor and he’s running two different products through the tube, one primary tube might be blocked at the metering roll but seed is flowing through fine.

“If we’re blocked in one primary outlet that’s a sixth of the drill width,” he says. “If you aren’t checking it you won’t notice any problems. We have to stop every so often and make sure a mix of seed and fertilizer is coming out at every row.”

McCallum and his brothers would like to get individual monitoring on each tank. That way they’d at least know they have material flowing through each of the primary hoses.

How it works: Starter fertilizer

Starter fertilizer convinces a wheat plant that it has enough nutrients to push out more tillers than it otherwise would. That’s important, because each tiller can produce a head and more grain.

Phosphorus is the main reason wheat responds to starter fertilizer. It’s critical to wheat metabolism for photosynthesis and respiration.

If there is plenty of phosphorus nutrition, the wheat thinks it has a high yield potential and pushes out more tillers. Dave Hooker says tillers produce 50% of wheat yield. “If wheat can maintain tiller numbers then it can maintain yield potential as well. If the plant is short of phosphorus and it thinks it can’t maintain tillers, it will start to abort tillers in order to favour the main stem.”

Most yield-forming tillers are made in the fall. Some tillers will start to form before freeze up but fail to develop, so it’s very important to use starter fertilizer if wheat is planted late.


Audio Podcast – Starter Fertilizer in Wheat