Ask the Agronomist – Top Questions & Answers for Corn

esn use on corn

Did you know that ESN’s original design concept was created with corn in mind? Corn was ESN’s primary target market because it was the largest nitrogen market in North America. As the largest market, we receive many questions about ESN use on corn, so we’re discussing the top three questions we have received from growers over the past year, answered by ESN senior agronomist Alan Blaylock.

What advice can be given on best application timing and placement for corn?

ESN was originally created around the concept of one pre-plant application for all your N needs. It has been tested in hundreds of university studies in this use and has consistently out-performed other nitrogen sources for pre-plant application. Many growers also use ESN as a post-emergence top-dress application, either instead of pre-plant or as a supplement to other partial pre-plant nitrogen applications.

For application recommendations for your region, click here.

To see local crop results in your region for ESN on corn, click here.

What’s the best fertilizer for corn, and when should it be applied?

First, in order to advise on what the best fertilizer for corn is, we would need a soil test to indicate how much of each nutrient you need to apply. With that information, we could formulate a blend that would meet your needs.

There are many good fertilizers from which you could get the proper nutrients. Corn needs a considerable amount of nitrogen (N) and potassium (K), with lesser amounts of phosphorus (P), sulfur (S), magnesium (Mg), as well as small amounts of trace elements depending on your natural or residual soil fertility. Zinc and boron are the most commonly deficient micronutrients in many areas.

Most of the nutrients needed by corn can be applied before planting, but it is usually recommended to split the total nitrogen needed into several applications. For example, about 25 percent before planting, 50 percent at 4-6 leaf stage, and the remaining 25 percent at tasseling. The total amount of N needed is typically in the range of about 150 to 200 lb N/acre (326 to 435 lb of urea/acre). Potash is required in a similar amount depending on your soil test. P, S, and Mg are needed at about 20-40 lb nutrient/acre. As an alternative to split nitrogen applications, one can apply ESN early in the season and eliminate the later in-season applications.

To discover what makes ESN the better nitrogen source for corn, click here.

I would like to know the effectiveness of substituting ESN for in-the-row application. I believe I could reduce my urea in the broadcast application while using ESN in my starter ration. I am looking to get my N values in late June or early July to support ear development. If this is a viable option?

If you are placing the ESN in the seed row in direct seed contact, you may not be able to achieve the N savings you are seeking simply because the amount you can place in the seed row on corn grown on 30-inch rows is rather small – probably not more than about 20 lb N/acre as ESN depending on soil texture and moisture. This amount of N in the row as ESN is not likely to significantly impact your overall N needs.

On the other hand, if you’re applying the bulk of your N in a band beside the row, the gains could be substantial.

In this Illinois study, one of the treatments is ESN banded six inches directly below the row. This is the best yielding treatment, and one banded ESN application yielded better than most of the split applications with urea. In many situations, banding nutrients can be more efficient than broadcasting as is illustrated in this study.

Have a question that you didn’t find here? Submit your questions or give us a shout on Twitter @SmartNitrogen.

Disclaimer: This information is not intended to be complete or detailed use recommendations for all geographies, crops, or applications. User assumes all responsibility for proper use and handling for specific geographies, crops, and applications. Please consult ESN recommendations and/or your Nutrien ESN representative for complete recommendations for use. Consult ESN recommendations for more information.
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