Corn School: Fine-tuning field trials with Bob Nielsen


With help from precision technology, corn growers are fully capable of conducting well-designed, logistically simple field trials that can help improve yield and profitability.

When it comes to on-farm research, “that’s the beauty of today versus 30 or 40 years ago when I started in this business,” says Purdue University corn expert Bob Nielsen. On this episode of Corn School, Nielsen, a professor of agronomy and one of the industry’s leading corn specialists, offers tips on how growers can tap into advances in technology and science and build field trials to answer key management questions on their farms.

For Nielsen, effective field trials start with asking the right questions. For example: ‘what’s the most effective planting depth?’ or ‘what’s the most effective rate of starter fertilizer?’ are two questions that can easily be tested in the field. Once growers have finalized their questions they can then design a trial and determine the number of treatments they need to test, he explains.

What about the field trial size? Nielsen quips that he’s often been called a “land baron” as he shoots for trials that range from 30 to 80 acres. He admits that trials can be smaller in size, but he recommends growers make trials big enough to include five or six treatments that can be replicated at least three times in the field. (Story continues after the video.)

When possible, Nielsen likes to construct whole field trials with passes that run the full length of the field. He also recommends that each plot be twice the width of the combine header, especially when doing nitrogen trials, which often have some kind of edge effect. The middle rows of each plot can then be harvested to generate the most accurate data.

In the video, Nielsen discusses the benefits of using variable rate technology for field trials. When testing nitrogen rates, for example, this allows growers to tap into research scientists and agronomists to build trial prescriptions that can be uploaded to variable rate controllers. “The farmer simply side-dresses the field and all the rate changing is done by the black box of the controller… and the farmer doesn’t have to worry about it,” he notes.

Nielsen also highlights the benefits of multi-year testing, why more data is better and offers tips on field performance factors growers should consider when assessing and analyzing data.

Click here for more Corn School episodes.


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Corn School (view all)Season 10 (2021) Episode 28

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