Late fertilizer runs show yield promise



Ill. — Aerial application of crop

protection products has been common practice for decades and now is being

looked at as an additional tool for hiking yields even further.

Schertz Aerial Service has been conducting on-farm research

into high-yield soybeans since 2012 with a focus on applying by air granular

potassium nitrate, ammonium nitrate or ammonium sulfate at the R2 growth stage

or later.

Initial experimentation, including applications of potassium

nitrate, resulted in moderate soybean yield increases, with an average yield

increase of two to seven bushels. The potassium nitrate applications also

resulted in observations of improved plant health with modest yield and quality


With the hypothesis that nitrogen could be a limiting factor

in high soybean yields, this past year one of the aerial service’s cooperators

requested a soybean yield trial where 40 pounds of nitrogen was applied, as

ammonium nitrate, in a side-by-side configuration in two applications.

The first ammonium nitrate application was made Aug. 4, at

approximately the R2 full bloom stage. The second application was made 10 days

later when the soybeans had progressed to the R3 or R4 growth stage. A large

section of the field was left as an untreated control.

Results from these treatments were dramatic, with harvest

yield maps documenting an average 10- to 15-bushel soybean yield increase over

the 70 bushel base yield for the Aug. 4 R2 stage application.

The second application on Aug. 14 resulted in a further yield

increase, though not as significant as from the earlier application.

Crop, Soil Health

Scott Schertz, owner/operator, Schertz Aerial Service, with

facilities at Lexington, Hudson and Gridley, recently hosted a crop

and soil health seminar that focused improving production while maintaining

sustainability with cover crops.

“Basically, it’s about crop protection and performance and

not only offering the crop protection products, but we’re excited about this

initiative on both protecting the water more so through the cover crops, but

also having an in-point application of additional fertilizer for soybeans,

which we saw a significant increase in yields last year,” he said.

Positive yield results are typically due to taking a defensive


“We can protect crops from weeds, disease, insects, that sort

of thing. This is really a new opportunity for us to take soybeans well beyond

what the normal yield had been,” Schertz said.

“We’re excited about it and we wanted to get (WinField

Solutions agronomist) Bob Beck, in particular, here to explain more of the

science behind it and also to help people on making the cover crops more

effective. We really need to plan for them and not just it being part of a

last-minute decision at the end of August.”

Dan Towery of Ag Conservation Solutions gave a presentation

on crops’ positive impact on water quality and agriculture’s productivity.

Schertz Aerial Service has been in what Schertz calls the

“specialty fertilizer” side of crop production for about five years.

“We got into a position to offer these products using

basically some of the tissue analysis work that we had done in conjunction with

Bob Beck. It got us to look at some opportunities in soybeans,” Schertz said.

“We’ve had some modest results the last several years trying

a few different things on soybeans, and last year was the first year that we

really saw something really out of the box.”

Perfect Timing

Due to the late timing of the fertilizer application,

airplanes provide a niche to get the products to the plants when most needed.

“Another thing that is important on this is we can actually

really control the access to the products. These are homeland security

sensitive products. We keep track of it and control the product all the way

through the field,” Schertz said.

“Application timing is one of them, another thing is you have

products that are stable, meaning they are not going to volatilize, and that

they are readily available to the crops.

“What it appears to be is you need a nice flush of nitrogen

right there when the soybeans would have an opportunity to use that, and this

particular form is really ready to go with very little moisture to get it into

the plant. It doesn’t have to go through the nitrification process like the other

nitrogen sources do.”

Seeding By Air

The aerial application of cover crop seeding into the corn or

soybean crops is picking up in popularity among farmers.

Many of the various cover crop seeds can be applied via air.

“It is important to know what people want, what their

expectations are, what they’re concerned about to try to give them our best

advice as to what fits for them. I do think that this is going to be of

increasing importance to help water quality and to also keep the productivity

in agriculture that we need,” Schertz said.

He also commented on the growing use of unmanned aerial

vehicles also referred to as drones.

“By and large, a lot of the farm media has the fascination

with drones. It is a real safety hazard for us,” he said.

“It’s a big concern and obviously there are a lot of

limitations on how they are operated and a majority of them would need a

special permit to operate and that still comes down to manned aircraft do have

the right-of-way, even an ag airplane.

“So there’s going to be a big concern on this interface

between ag planes and drones. Be cautious of the ag planes operating in the



Tom C. Doran can be reached at 815-780-7894 or Follow him on Twitter at: @AgNews_Doran.


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