Precise Placement Adjusts Rates

Evaluating and fine-tuning starter and nitrogen fertilizer are annual efforts for the Farm Journal Test Plots program. On average, the plot research has documented a 7 bu.
to 10 bu. per acre response to starter placed 2" to the side and 2" down from the surface (2x2) and a 3 bu.
to 5 bu. response to in-furrow application. Using dual placement, also called the relay effect, yield has increased 15 bu. to 20 bu.

“It’s like the fertilizer positions are handing off a baton. The roots find the nutrients as they need them,” explains Farm Journal Field Agronomist Ken Ferrie, who is based in central Illinois.

For years, Ferrie has found significant and consistent response using the Huckstep shoe. Due to the weather conditions in 2016, applying 7-22-5 with the Huckstep shoe resulted in even stronger responses–30 bu. to 50 bu. compared with the check (no starter).

With many new attachments on the market, an emphasis on placement is more important than ever. In 2016, Ferrie also evaluated the Great Plains AccuShot, Schaffert Generation 2 fertilizer disks and the Precision Planting FurrowJet using the same hybrid, populations, weather conditions and planting dates to collect, weigh and evaluate results by management zones. Farm Journal Associate Field Agronomist Missy Bauer conducted tests in southern Michigan with similar protocols.  

Placement #1. The AccuShot’s metering system triggers a dose, or squirt, of liquid fertilizer every time a seed drops. The operator controls how much and how close to the seed the fertilizer is applied. This concept is ideal to evaluate placement in narrow or twin rows. For a strong response, starter needs to be within a 3" circle around the seed.

“In 30" corn, plants are only 6.5" apart, and when you dribble starter in-furrow, there’s not a lot outside of the 3" circle,” Ferrie says. “But in twin rows, plants are 13" apart and starter is less effective dribbled in-furrow. It’s not lost fertilizer, but it acts more like a fall broadcast application.”

To address this, Ferrie has found a 5-gal. rate in-furrow in 30" rows needs to be 10-gal. in twins for the same effect.

In the first 2016 plot field, the crew used a Great Plains 16-row planter, half twins, half 30", outfitted with the AccuShot system. The study used 7-22-5+Zn and applied a range of rates from 2.5 gal. to 20 gal. at ¾" away from the seed. The field was planted April 20 with Pioneer 1197 at 32,000 and 36,000 plants per acre (ppa).

In twin rows at 32,000 ppa, the plot compared 7-22-5+Zn applied at 2.5-gal. and 5-gal. AccuShot squirts and a 10-gal. dribble. The 5-gal. squirt had a slight average yield advantage compared with the 10-gal. dribble. The 5-gal. squirt had a 3-bu. to 7-bu. gain compared to the check, with 2.5 bu. paying the fertilizer bill. In this scenario, the 5-gal. squirt was the economical choice because the 10-gal. dribble didn’t pay the bill.

In 30" rows, at 36,000 ppa, the plot had 7-22-5+Zn applied in 2.5-gal. and 5-gal. squirts, a 5-gal. dribble and a 10-gal. dribble. Compared to the check, there was an average 2-bu. advantage using the 2.5-gal. squirt, a 8-bu. gain for the 5-gal. squirt, a 6-bu. advantage using the 5-gal. dribble and a 1-bu. gain for the 10-gal. dribble (which started causing seed burn). Overall, the 5-gal. squirt yielded 7 bu. more than the 10-gal. dribble.

“When fertilizer is placed close but not on the seed, you can use a higher salt, cheaper starter,” Ferrie says.

In 30" rows at the lower population, 32,000, sunlight was wasted. The 36,000 population allowed the plants to capture more sunlight and bushels.

In twin rows, sunlight didn’t hit the ground at 32,000 ppa so once you close the rows, pushing the population can actually make the hybrid go backward, Ferrie says. “Therefore, hybrid selection, plant architecture and population are critical in narrow rows,” he adds.

Overall, the results show precise, strategic placement can cut starter rate in half while yielding more.

In southern Michigan, Bauer found similar results in 2015 and 2016. Using a Great Plains eight-row planter with AccuShot and Redline 6-12-2 low-salt fertilizer, the study compared a 1.5-gal. squirt in-furrow (½" from seed), 1.5-gal. squirt (¾" from seed), 3-gal. squirt (½" from seed), 3-gal. squirt (¾" from seed), 3-gal. dribble and 6-gal. dribble. The 1.5-gal. (¾" from seed) application yielded 2 bu. to 8 bu. more compared with all other applications.

“We found the 1.5-gal squirt
in-furrow acted the same or better than the 3-gal. dribble,” Bauer says. “The yield results prove with proper placement, there’s potential to cut rates in half and see similar responses.”

Across all applications, applying starter ¾" rather than ½" from the seed yielded higher results. In sandier soils in southern Michigan, being ½" from the seed proved to be too hot.

Placement #2. Going a step further, the Illinois Test Plots crew evaluated different placements and starter combinations. The FurrowJet applies liquid fertilizer ¾" from the seed on both sides of the furrow using two wings that slice the sidewall. The Schaffert attachment cuts a slice 2" away from the seed and an injection nozzle to applies fertilizer.

Planted May 6 and 7, the starter rates and blends included 3 gal. 10-34-0+Zn+Avail in-furrow, 10 gal. 7-22-5+Zn in the wings and 3 gal. in-furrow and 10 gal. in wings, via relay. Ferrie recommends adding zinc to starter, and Avail gives starter more horsepower (3 gal. acts like 5 gal.)

In 2016, the in-furrow starter application averaged an 11-bu. advantage compared with the check. The wings application averaged a 14-bu. gain, and the relay effect yielded a 26-bu. advantage.

Within 24 hours of planting this field saw an excessive amount of rainfall, which played a big role in the results. Ferrie monitored this plot throughout the season. For example, in aerial photos taken with a drone, he was able to see the response to the starter by zone across the field through the season.

“The large yield responses show the effect of starter fertilizer placement and the horsepower it provides to mitigate early season stress,” Ferrie says. “The fact we were able to weatherproof this plot by replicating it across the field makes the large yield increases more believable.”

The test plots crew also evaluated 3 gal. 10-34-0+Zn+Avail in-furrow, 10 gal. 7-22-5+Zn FurrowJet (relay) and 10 gal. 7-22-5+Zn Generation 2 (relay) applications. On average, the in-furrow application saw a 16-bu. gain, the relay FurrowJet application had a 27-bu. gain and the Relay Generation 2 had a 24-bu. gain.

“In order to catch up to the Huckstep shoe, these applications have to be in a relay format,” Ferrie says. “Apply some fertilizer in-furrow and some in the wings.”

Phosphorus’ Role In Starter

Building on decades of starter fertilizer experience and knowledge, Ferrie took his research a step further to learn more about phosphorus’s role in starter fertilizer blends.

Starter fertilizer has two sources for phosphorus. Polyphosphates are orthophosphate molecules joined together in the manufacturing process by heat and water removal. Poly fertilizers have a higher analysis compared with the ortho form. When added to the soil, the poly fertilizer combines with water to break down; the ortho fertilizer is readily absorbed by the plant.

Test Plot #1. To analyze the data, Ferrie and crew measured starter fertilizer on a gallon per acre basis.
In central Illinois, they compared
3 gal. 10-34-0+Zn+Avail (poly) and
3 gal. 3-18-18+Zn+Avail (ortho). That breaks down to 3-10-0+Zn+Avail and 0.9-5.4-5.4+Zn+Avail per acre.

“This is where it’s easy to get confused,” Ferrie says. “If you applied
3 gal. 3-18-18, this does not mean you applied 54 lb. of phosphorus in your starter fertilizer.”

The 3-10-0+Zn+Avail (poly) yielded 16 bu. more than the check. The 0.9-5.4-5.4+Zn+Avail (ortho) application yielded 5 bu. better than the check. The additional 5 lb. per acre of phosphorus in the poly fertilizer resulted in a 10-bu.-per-acre gain compared with the ortho fertilizer. This yield response is directly correlated to the pounds of phosphorus applied.

In addition, Ferrie also evaluated starter response to phosphorus rates and placement. As a rule of thumb, data shows plants directly respond to applied phosphate. Therefore, the higher amount of phosphate applied closer to the seed, the higher the response. These findings often spur debates regarding ortho versus poly starter fertilizers.

When applying starter in-furrow, don’t neglect the risk of starter burn.

“It’s important to consider soils and environment when selecting starter blends,” Bauer says.

Being sensitive to the potential for starter burn, Bauer reports that on her area’s sandy loam soils, they typically apply 3 gal. of a low-salt starter in-furrow.

Typically, Ferrie recommends a 10-34-0 poly starter fertilizer to avoid starter burn (no potash).

However, if you want potash in your blend, ortho starter fertilizers have the potential to shine. These blends use potassium hydroxide, which is not a salt, so it’s considered safer and allows for higher rates in-furrow. However, using an ortho starter fertilizer does not guarantee you avoid starter burn, Ferrie adds.

“It comes down to potassium and rates. Orthophosphate starter fertilizers open the door to new possibilities in-furrow,” Ferrie says. “These can particularly be a good fit for farmers looking for potassium in the starter blend with a higher rate in-furrow application.”

Test Plot #2. Ferrie’s plots also studied three in-furrow applications: 4 gal. 6-18-6+Zn+Sulfur (ortho),
4 gal. 3-18-18+Zn+Avail (ortho) and 4 gal. 10-34-0+Zn+Avail (poly). Averaged across all management zones, the first (ortho) application yielded 3.1 bu. compared with the check, the second (ortho) received a 4.9-bu. gain and the third (poly) had a 4.7-bu. yield response.

Ferrie says quality in the source of starter is key. Ortho fertilizers are worth the extra cost if there isn’t access to a quality 10-34-0 poly starter fertilizer in your area. A good clean 10-34-0 poly starter fertilizer should be green with no sediment or offensive smell, Ferrie says.

Across all starter plots in central Illinois, yield data consistently shows the direct correlation to starter response and pounds of phosphorus applied. The higher amount of phosphate you can apply closer to the plant, the higher the response. 

On average, past data shows there’s a 3-bu. to 5-bu. response to in-furrow applications and a 7-bu. to 10-bu. response to 2x2 applications.

“Due to starter attachment costs, many farmers only apply starter fertilizer in-furrow, which works,” Ferrie says. “However, by only applying in-furrow at a lower rate, you’re admitting on the front end your responses will be lower.”

In this case, Ferrie recommends farmers use the highest rate possible (whether that be a poly or ortho starter fertilizer) to achieve enough yield response to pay the bill but not burn the seed. However, in 2x2 applications, Ferrie says the economical choice can be a poly starter fertilizer with potash.

“If you’re applying 2x2, you don’t have to play it as safe as in-furrow,” Ferrie says. “Therefore, using a polyphosphate blend such as 7-22-5 or 6-18-6 will help farmers achieve a higher yield response at less cost.”

Test Plot #3. To take the results a step further, Ferrie also evaluated the relay effect. In past Farm Journal Test Plots, dual placement has shown a 15-bu. to 20-bu. yield increase. In 2016, the crew evaluated 4 gal. 3-18-18+Zn+Avail ortho in-furrow as well as 10 gal. 7-22-5+Zn 2x2
and 4 gal. 3-18-18+Zn+Avail ortho in-furrow. The in-furrow application had an average 5-bu. increase and the relay effect boosted yield by
10 bu. per acre.

“Once again, you can see the power of the relay effect,” Ferrie says. “It’s like the starter fertilizer placements hand off a baton, so the corn roots find the nutrients as they need them.”

When farmers adjust the phosphate amount in starter fertilizer blends, don’t forget to reduce the amount in other applications to maintain the total goal, Ferrie says. For example,
if you apply 10 gal. 7-22-5, you will need to pull back 50 lb. of diammonium phosphate (DAP).

Regardless of the placements or blends, it’s essential to consider the crop’s needs and economics of starter fertilizer in all situations.

Choose the combination that best fits the farmer’s yield goal, soil types and pocketbook.  

Thank You to Our Test Plot Partners

Case IH, Jay Barth, Bill Hoeg and CJ Parker; Great Plains, Mike Cleveland and Doug Jennings; New Holland, Mark Hooper, Daniel Valen, Ken Paul, Mike Kizis and Sheldon Gerspacher; Precision Planting and Cory Muhlbauer; Burnips Equipment and Carl VanderKolk; Versatile and Adam Reid; Central Illinois Ag and Kip Hoke; Kinze Manufacturing, Susanne Veatch and Phil Jennings; Marco N.P.K. Inc; Schaffert Manufacturing and Paul Schaffert; SFP; Unverferth Manufacturing and Jerry Ecklund; Wells Equipment; Apache Sprayers; Trimble, Frank Fidanza and John Pointon; AirScout and Brian Sutton; AgXcel and Ramiro Trevino; Geovantage; Ag Leader and Luke James; Yetter Manufacturing, Pat Whalen and Scott Cale; Blu-Jet and Nick Jensen; Fast and Dan Liening; Greenmark Equipment and Chad Kasprazak; Yamaha; West Central and Joe Schubert; Don Schlesinger and Dan Reynolds; Shorty Olson; Crop-Tech Consulting, Isaac Ferrie, Matt Duesterhaus, Mike Carl, Logan Koester, Aaron Herrmann and Chelsea Ferrie; LDK Farms and Leon Knirk; Bob Minor; B&M Crop Consulting, Bill Bauer, Amanda Anderson, Jared Haylett