Nitrogen Sensor Unplanned Test Convinces Grower of Value

Kurt LawtonAg Leader, Farmers, Fertilizer, Insights Weekly, Remote sensing, Software, Variable rate

Insights WeeklyYou know how sometimes things happen in farm fields that are either out of your control, or perhaps something known as operator error. Well, some of those oops provide valuable learning experiences, don’t they?!

Such was the case with central Nebraska farmer Kurt Kroeger. Now Kroeger is a fairly advanced precision ag aficionado, playing with many things on his 1,250 acres. He’s a big fan of Ag Leader because the tools work well with all colors of equipment that he owns. And he’s become a whiz at SMS Advanced software to write his own variable-rate (VR) seeding and fertility prescription maps.

Another technology that has intrigued him since the late 1990s is the nitrogen crop sensor. “I followed the GreenSeeker sensor since it came out. Then I watched the Holland sensor become Ag Leader’s OptRx technology—and became one of the first to buy them.”

So, this past spring he mapped out a good test in a couple fields under pivots. “In one section of the corn field I applied a high rate (44 lbs./acre) of 32 percent nitrogen plus thiazole as a high yield check. In the second section I applied 32 percent based on the OptRx sensor, and in the third section I applied the nitrogen according to my fertilizer supplier’s best VR map based on soil type and fertility,” Kroeger says.

Then, that unplanned ‘fluke test’ happened, as he calls it. “The coolest thing in the world happened. When the corn was a foot tall, my mini-corner pivot got stuck all night and watered one spot heavily. As you can imagine, in another couple weeks when I applied the fertilizer, I had a nice and visible section shaped like a Nike swoosh mark in the field where all the nitrogen had leached away,” he says.

The OptRx sensors recognized the deficient plants in his ‘swoosh’ area and applied 50 to 56 gal., which was quite a bit higher than the whole field average of 34 gal. And compared to the 36 gal. on the retailer VR section, the OptRx not only saved 2 gal. it produced more yield too. These results not only sold Kroeger on the OptRx technology, but it changed his whole point of view on fertility in his sandier soils.

“The OptRx produced more uniform and higher yields, based on a philosophy of feeding all plants that need more fertility, which is different then the soil map VR philosophy that feeds the good areas and starves the poor areas of a field. It makes the whole field more uniform. I want every acre to pay for itself.”

Needless to say, Kroeger is sold on using the OptRx on all his corn next year. “If I had achieved the same results across my whole farm as I did in the plots, the system would have paid for itself this year alone,” he adds.

His next learning challenge…figuring out a way to use it on his sprayer to apply N using drop nozzles.

Visit these links for more information.

The OptRx Crop Sensor

Blog posts on OptRx technology

SMS Advanced software

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