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Current Project: Starter Nitrogen for Corn


Research Team:

Quirine Ketterings, Karl Czymmek (PRODAIRY), Greg Godwin, Sheryl Swink, Carl Albers, Peter Barney, Stephen Canner, Aaron Gabriel, Mike Hunter, Tom Kilcer, Joe Lawrence, Alex Wright, Eric Young, staff from Agricultural Consulting Service.

Funding Sources:

Northern New York Agricultural Development Program (Northern NY sites), and Federal Formula Funds.

2011 Field Protocols:


Popular Press Articles:

Additional Materials:


Currently, many dairy producers in New York State have reduced starter P use ( but spend a least $20/acre for starter fertilizer N. Cornell guidelines reflect high probability of a starter N response where manure has not been applied recently, but, unlike P, we have not adequately tested the possibility of eliminating starter N fertilizer on manured sites or in other words, replacing the need for fertilizer by applying manure. The results of a pilot project on starter N needs on a western NY dairy farm showed N could be eliminated from the starter without a penalty in corn yield or silage quality (potential milk production per ton of silage), although a first year corn (after alfalfa) field yielded corn silage with a slightly lower protein level when N was eliminated from the starter. In 2007, we also analyzed the silage for feed quality parameters. The data showed eliminating starter N did not impact any of the silage quality parameters in the 4th year corn site in 2007. However, adding 60 lbs N/acre did significantly increase crude protein levels in 1st year corn. Yet, this increase in crude protein did not seem to impact the overall silage quality expressed in tons/acre or milk per acre. Based on these results, we successfully applied for Federal Formula Funds which enabled us to conduct additional trials (2009-2011). The project was completed December 2011.

Elimination of starter N use without yield/quality penalty in fields with fall or spring applied manure can lead to substantial savings in fertilizer as well as labor costs during the already busy planting season. Timely planting is essential in the short growing season of NNY so not having to refill fertilizer boxes during the planting season will have benefits for corn yield and quality. Recognition of the fertilizer value of the manure might further stimulate producers to distribute the manure over a larger acreage, given fertilizer prices have more than doubled in recent years. It is not known under what manure management systems (fall application, spring with or without incorporation) starter N can be eliminated without a yield or quality penalty or if results of the pilot study apply to other regions in the state with different soil types and growing seasons.

In this 3-year project, we proposed to test the value of manure in replacing purchased starter N fertilizer on dairy and livestock farms. The objective was to determine the starter N need for manured fields of varying manure application history (fall or spring application, incorporated or surface applied). The project builds on recent studies that showed: (a) no starter P is required for corn on fields testing high and very high in soil P, (b) no manure or fertilizer N beyond starter is required in the first year of corn after sod kill, and (c) results from the western NY case-study farm that indicate manure application can replace starter N fertilizer (preliminary results; 1 farm, 2 years of data).

Our main conclusions are:

  • Starter N should be used for fields with no manure history and no current year manure applications (deficient ISNT-N).
  • If the ISNT-N is classified as optimal, manure can be used to replace starter N without a yield or quality decline.
  • Manure can replace starter N for sites deficient or marginal in ISNT-N as well, but only if sufficient N from manure and other sources (cover crops, soil N, sidedress N) is available (CSNTs between 750 and 2000 ppm); a yield response to starter N would have been likely if the ISNT-N was deficient and additional N applied was insufficient as well.
  • A new interpretation should be added for the CSNT for 2nd or higher year corn: “Marginal” (250–750 ppm), where a response to starter N could be expected in some years. To reduce risk, it is recommended that farms strive for CSNTs between 750 and 2000 ppm, using 8-inch stalks taken between 6 and 14 inches above the ground.
  • We recommend producers analyze 2nd or higher year corn fields for both ISNT-N and CSNT, to identify sites where a starter N application can be omitted.

For further information:

Questions? Contact Quirine Ketterings at 607-255-3061 or