The Impact of Late-Season Nitrogen Application, USGA Central Region Update

Posted on April 20th, 2021

An untreated check plot shows the impact a late-season nitrogen application can have on cool-season grasses.  

By: Zach Nicoludis, agronomist, Central Region

With favorable weather conditions throughout much of the Midwest, agronomic teams have had the opportunity to hit the ground running with course assessments and all the maintenance practices that must be completed in the spring. For those that implement a late-season fertilization program, it is likely that the benefits of this strategy are being realized now.

A recent visit to a course in central Ohio led to a discussion on the benefits of fertilizing cool-season grasses late in the season. In early December of 2020, ammonium sulfate was applied to the fairways at a rate of 1 pound of nitrogen per 1,000 square feet. The results speak for themselves when comparing the untreated check plot to the rest of the fairway. This application led to early spring greenup and there is no need to apply nitrogen at this time, which would only promote the impending surge of growth that comes as soil temperatures increase. The article “The Benefits of Late Season Fertilizer” – written by Dr. John Street, Pamela Sherratt and Dr. Karl Danneberger of Ohio State University – offers an in-depth look at the benefits of this practice, how to time this application, and highlights some of the research that has been performed on this topic.

The fairways were not the only playing surface that received a late-season fertilizer application at the course I was visiting in Ohio. The slow-release fertilizer IBDU was applied to the putting greens as the 2020 season was winding down. Similar to fairways, overall turf health was excellent this spring.

Don’t wait until fall to determine whether this practice will be added to your agronomic program. Now is the time to plan for a late-season nitrogen application so adjustments can be made to how much fertilizer is applied throughout the season. To discuss late-fall fertilization or any other topics that relate to golf course agronomic programming, contact your regional USGA agronomist about setting up a Course Consulting Service visit.

Central Region Agronomists:

Paul Jacobs, agronomist –

Zach Nicoludis, agronomist –

Information on the USGA’s Course Consulting Service

Contact the Green Section Staff

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