Exploring Stream Bar Strategies

Growers know that missing the optimal planting date can significantly reduce corn yields. With small planting windows, sometimes growers must decide between waiting for the custom applicator to apply their nitrogen prior to planting, or go ahead and plant without any nitrogen down and try to figure out how to get it applied afterward.

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Here is where the saying, "necessity is the mother of invention" proves itself to be true. In 2019, we decided to incorporate stream bar technology into corn production—a technology used in small grain production. We wanted to test whether or not stream bars could be an effective means of applying nitrogen after planting prior to emergence and as an in-season nitrogen placement option.

What is a Stream Bar?

A stream bar is a type of sprayer nozzle attachment that focuses multiple low-pressure streams of liquid downward at an even spacing. The stream bar we tested in 2019 generated 4 streams with 3 1/3 inches between each stream. The total width of 1 stream bar is 10 inches.

Compared to a traditional broadcast application, we expected the stream bar to be a more efficient placement for nitrogen.

the stream bar places 4 streams of nitrogen spaced 3 1/3 inches apart over the corn row

The Principle Behind the Stream Bar

Using a stream bar in corn production serves two purposes:

  1. To improve nitrogen efficiency, and
  2. To give growers greater flexibility with nitrogen application timing, rather than depending on pre-plant broadcast applications or fall applied nitrogen.

When we talk about the efficient use of nitrogen, we mean that nitrogen is available:

  • In the right place (the plant’s root zone)
  • At the right time (when the plant needs it)
  • In the right amount

We believe that the stream bar may be able to improve nitrogen efficiency through better placement and timing when compared to other application methods.

The Stream Bar as a Pre-Emerge Nitrogen Application Method

In our 2019 research trials, a pre-emerge application of 60 lbs/acre of nitrogen as UAN 28% with the stream bar yielded 13.4 bu/acre more than a broadcast pre-plant application of 60 lbs/acre of nitrogen in the urea form.

We also tested a 2x2x2 planter applied placement of 60 lbs/acre of nitrogen as UAN 28%, and the stream bar out-yielded this method by 5 bu/acre.

Stream bar and 2x2x2 nitrogen application methods yield comparison chart

The Stream Bar as an In-Season Nitrogen Application Method

Growers have been trending towards applying nitrogen in-season which means they must decide which application method will work best for their operation. We’ve tested various in-season nitrogen application methods over the past several years and new to this year was the stream bar.

In order to avoid applying the nitrogen directly onto the corn plants' leaves—which would burn the plant—we offset the stream bar by 4" and turned it to a 45° angle.

Between top-dress applications of urea, coultor applications, drop hose applications, and stream bar applications of UAN 28% (all at V4) the stream bar application method topped the charts in 2019 with a 17.4 bu/acre yield increase over no additional nitrogen. The drop hoses came in second with a 12.8 bu/acre yield increase followed closely by top-dressed urea with a 12.5 bu/acre yield increase.

stream bar yield response for in-season nitrogen applications

We Believe Stream Bars are a Viable Option for Applying Nitrogen in Corn Production

Growers should not feel pressured into applying nitrogen in the fall with the concern that they will not get it on before planting. After all, applying nitrogen 5 to 6 months in advance is not "risk-free". We do not know what the weather will bring during that time and you could very easily lose a good chunk of your investment.

Based on the 2019 research trials, stream bars seem to be an effective means of placing the nitrogen where it needs to be—in the corn plant's root zone—while providing the timing flexibility many growers need with these small planting windows.