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The Case for Starter Fertilizer

New planter and application technology can lighten the load of applying starter fertilizer at planting for higher yield and drier grain at harvest.

By Marilyn Cummins

No one has a crystal ball to predict harvest conditions, but it’s a sure bet that many Corn Belt growers do not want a repeat of last year’s wet grain and early frost worries. Those who had to plant late or replant in 2020 due to a wet spring in their areas may already be in for the extra cost and hassle of drying down grain this fall.

That was on the mind of a team of agronomists at Purdue as they looked at the results of their starter fertilizer trials from 2014 through 2019. While they did look at yield effects, which varied, they also noticed a very consistent result: a decrease in grain moisture at harvest, which could cut down on drying costs or even enable an earlier harvest to beat a frost.

Jim Camberato and Bob Nielsen, Purdue agronomy professors and Extension specialists, led the research at six Purdue farms spread out in the state and with varying soils. Camberato says that while yield increases averaged about 10 bushels an acre with 2”x2” nitrogen and phosphorus starter fertilizer in the 42% of the corn-after-corn trials that saw a yield response, they saw a decrease in grain moisture in nearly 90% of those trials.

“So even when we don’t see a yield increase, we still often see a moisture decrease,” he says. Grain moisture was about 1.5% lower on average with the 2”x2” starter treatments, and the biggest difference recorded was just over 2% lower moisture than corn with no starter.

Why the difference? “My theory is that having the nutrients in a high concentration near the young plant somehow signals the plant,” Camberato says. “It senses it’s in a good environment, so it’s going to put out leaves at a certain rate and keep that linear growth rate established when it was young.”

If you start seeds and young plants in an ideal environment – from moisture to soil tilth to nutrition – and if you can continue to provide all the things they need, he says, “they’re on a higher path than if they were just left to their own devices early on.” He says he believes that such signaling can work in reverse, so that the impact of early stress on a plant “can change the path of that plant even after those stresses are relieved.”

Benefits of an Early Boost with Starter Fertilizer

Camberato says even if there is not always a direct yield effect of using starter fertilizer, there are other agronomic and economic advantages. One is that having nitrogen available to the plant early allows some flexibility in when the rest of the nitrogen is provided. Some growers use pre-plant nitrogen for that reason, but he says the research doesn’t show the same early effects as with starter fertilizer at planting, and corn plants can suffer if side-dress nitrogen is delayed until growth state V8 or later.

That would go along with advice from University of Illinois that “the main lesson we’ve learned from our N timing and N form studies over the past five years is that corn plants need to have a substantial amount of N available in the soil near the row after plants emerge and before their nodal (main) root system starts to develop,” Emerson Nafziger, now-retired crop sciences professor and Extension agronomist, said in 2019.

The corn on the right received the same amount of nitrogen as the corn on the left, but it was applied in dual high-concentrated bands using Conceal on the planter. PTI Farm, Pontiac, Illinois.

The corn on the right received the same amount of nitrogen as the corn on the left, but it was applied in dual high-concentrated bands using Conceal on the planter. PTI Farm, Pontiac, Illinois.

Jason Lee, part of the Purdue research team as a Ph.D. candidate and now North American agronomist at AGCO, says they found that starter fertilizer doesn’t necessarily increase plant dry matter, it does speed up plant development. “The plant puts on new leaf collars faster, and will silk earlier, which means fewer days between planting and silking,” he says. “By maturing and reaching black layer faster, the plants have more days of in-field drying before harvest, reducing drying costs.”

In 2019, some late-planted corn lost six weeks of fall drying and maturing weather, causing many growers to have to leave grain in the field longer and incur major costs of time, equipment and fuel to dry down grain for safe storage or sale without penalties at the elevator. Camberato says in certain environments, the early boost from starter fertilizer also can mean being able to harvest earlier.

“I would recommend always putting on starter fertilizer,” Lee says. “It’s a good practice to do regardless of planting date. Now that we know it accelerates plant development, using a starter fertilizer is just as important with late planting.” He also notes that growers shouldn’t look at it as an extra fertilizer input cost, since the starter application is still part of the overall nutrient plan. He also sees a value in the insurance it brings if side-dressing is delayed, as well as savings from lower grain-drying costs.

Why Don’t All Growers Use Starter Fertilizer?

Both Camberato and Lee acknowledge reasons growers may be reluctant to shift part of their fertilizer program to starter fertilizer. “They may not want to carry the weight of the fertilizer on the planter and risk compaction, or they don’t want to pay for the attachment that’s going to inject the fertilizer,” Camberato says. “Or they don’t want to be slowed down by having to fill up the fertilizer tank.”

Lee says he can see why farmers may hesitate to take time to apply starter fertilizer if they’re still trying to get seed in the ground on May 25, even though he believes the fast start can pay off with faster plant development and drier grain. A colleague on the Purdue team, graduate student Cody Hornaday, now technical agronomist for White River Cooperative in Loogootee, Indiana, analyzed the potential return on investment from using starter fertilizer in continuous corn, including equipment costs. (See a summary in “The ROI for Starter Fertilizer in Corn.”)

In his agronomist role at AGCO, Lee is managing research trials with the company’s innovative Fendt® Momentum™ planter, which he says is designed to help overcome many of the perceived obstacles to using starter fertilizers.

Gain Productivity, Minimize Compaction with the Fendt® Momentum™ Planter

With the launch of the new Fendt® Momentum™ planter, available for order now for the 2021 planting season, AGCO offers new possibilities for high-speed, high-productivity planting and nutrient application in one pass, says Larry Kuster, AGCO marketing specialist for seeding and tillage. With the planter’s optional 1,000-gallon liquid fertilizer tank, “we’re doubling the capacity of existing planters or more, therefore at least doubling the number of acres an operator can cover between fills.”

To minimize the effect of the additional weight of the fertilizer on the Momentum planter, Kuster says the optional Load Logic™ weight management system uses Smart Spindle technology to monitor and manage weight distribution across all wheels on the planter, and is automatically adjusting tire pressures while operating in the field. Using the latest very-high flexion (VF) tires and the central tire inflation system, in-field PSI is kept at the minimum tire pressure required for the weight at any given time, to increase the footprint and reduce compaction.

In addition, the planter has in-line tandem center wheels that travel the same path as the tractor wheels and eliminate planter pinch rows. Operators can set Load Logic to distribute weight equally on all planter wheels or put most of the weight on the center wheels in controlled traffic mode.

New Application Technology for an Easier Start

The unique Smart Frame™ of the Momentum planter features two toolbars 59 inches apart, Kuster says, “leaving ample room and ground clearance to accommodate virtually any kind of fertilizer application attachments on the primary chassis toolbar or the row units themselves.” The liquid fertilizer package option on the planter offers advanced vApplyHD® controllers from Precision Planting® for section or row-by-row control. The planter comes standard with quick-attach brackets on each row unit for Keeton® seed firmers and Precision Planting’s FurrowJet® as one option for starter placement, and the SmartFirmer® seed-firmer sensor for in-furrow readings of soil conditions.

 

The Fendt Momentum planter also can be equipped from the factory with new Precision Planting Conceal® nutrient placement system on the front of the row unit in place of the planter gauge wheel. A groove in the wheel conceals a knife that allows growers to place nitrogen in a high-concentration dual or single band 3 inches away from the seed trench in depths near 1.5 inches. Its design gives consistent nutrient placement relative to the seed while not adding the row-unit length or bulk of older 2″ x 2″ application attachments.

Precision Technology Institute study results, Pontiac, Illinois, 2017-2019. All treatments applied using 32% UAN liquid nitrogen. WNF = pre-plant “weed-n-feed” herbicide/fertilizer application. Roll mouse over the bars in the graph for full legend of each method.

Three years of corn starter fertilizer research trials at the Precision Technology Institute farm at Pontiac, Illinois, have shown a nearly $60-per-acre gain in revenue when 25% of nitrogen is applied as pre-plant weed-and-feed, 25% dual-band on the planter with Conceal, and 50% applied side-dress, compared to a program of 50% weed-and-feed and 50% sidedress (see chart above). The input cost for nitrogen was the same between the two protocols, says Jason Webster, Precision Planting commercial agronomist; only the timing and application method differed, with Conceal putting nitrogen closer to the corn, when it needs it.