March 2, 2007

Contact: Dr. Quirine M. Ketterings, Cornell University, 607-255-3061;
NNYADP Co-Chairs Jon Greenwood, 315-386-3231; Joe Giroux, 518-563-7523

NNYADP Research Evaluating Six Ways to Help Corn Growers
Save Money, Reduce Nutrient Loss; Learn More March 14-15

The Northern New York Agricultural Development Program, a farmer-led research and educational outreach organization for New York�s six northernmost counties, is funding research that is evaluating six testing tools to help producers know when nitrogen is needed for corn crops. Cornell University researchers are working with farmers to develop ways to assess when farmers can save the cost of applying additional nitrogen (N), a key nutrient for corn. Reducing the amount of N applied to corn also reduces nitrogen leaching to groundwater. Details on this regional research will be presented at Crop Congresses in Carthage on March 14 and in Canton on March 15.

Program Co-Chair Jon Greenwood says, �The Northern New York Agricultural Development Program considers precision nitrogen management for corn research a good way to marry science and practicality with the goal of developing efficient, cost-effective production practices that are environmentally-friendly and can be used by farmers throughout the region.�

Conclusions from 2005-2006 Field Trials in NNY
In 2006, field trials were conducted with four second-year corn crops and one first-year corn crop following sod. The first-year corn at the Cornell Baker Research Farm in Willsboro, NY, and two second-year corn crops in St. Lawrence County did not respond to additional N application. Second-year corn in Jefferson and Essex counties responded to sidedress N.

Project leader Dr. Quirine M. Ketterings of Cornell University�s Department of Crop and Soil Sciences says, �Combining the data for six first-year corn crops in Northern New York with ten other trials from around the state showed no yield or forage quality response to sidedress N. From the research station trials that included a no N treatment, we conclude that first-year corn will benefit from a small starter nitrogen application of about 30 lbs. per acre and does not require any additional N beyond the starter.�

This conclusion suggests there is no need to use any N management tools, such as the PSNT, chlorophyll or ISNT. For farmers that would normally sidedress first-year corn, this could mean substantial savings in fertilizer and application costs � a minimum of $30 to $40 per acre.

Twelve field trials (5 in Northern New York, 7 elsewhere in NYS) resulted in five sites that responded to extra sidedress N while seven sites did not show a yield increase upon N addition beyond the starter. These results show a need for tools that can help producers determine under what conditions extra N is needed.

Six Nitrogen Management Tools Under Evaluation
The research team working in Northern New York includes Ketterings, Cornell graduate student Joe Lawrence, Karl Czymmek, a senior extension associate with Cornell�s PRO-DAIRY program, and Cornell Cooperative Extension field crops educators Peter Barney of St. Lawrence County and Michael Hunter of Jefferson County. The team is evaluating three tests to predict the N need of second and greater-year corn grown after sod and three end-of-season tests.

The Pre-Sidedress Nitrate Test (PSNT) predicted a need for additional N for all five sites, however, only two of the second-year corn sites showed a response to sidedress N. Ketterings says the inaccuracy of PSNT for predicting N needs in first-year corn is well-documented. She notes that PSNT is usually more accurate for second-year and later corn and that the 2006 test results may have been affected by a large of amount of spring rain in Northern New York.

Another in-season test evaluated is the chlorophyll at PSNT time. Based on a one-time reading of all Northern NY field sites in 2006, each site would have needed additional N. Lawrence says, �The yield results indicating only two of sites responded to sidedress N suggest that more work is needed to determine the critical values for New York State if the chlorophyll at PSNT time test is to be useful.�

On-farm trials in Northern New York from 2002 to 2004 evaluated the performance of a new soil N test � the Illinois Soil N Test, also known as ISNT or the aminosugar N test. Lawrence says, �The ISNT showed the most promise for use in New York so far. The critical value determined by ISNT and organic matter worked well in predicting the N needs of second-year corn at all sites in Northern New York and at eleven of twelve sites statewide in 2006. The ISNT was more accurate than the PSNT in predicting a response to sidedress for second-year corn.� Additional test sites will be added in 2007, including five in Northern New York, to draw final conclusions on the performance of this test.

The end-of-season tools under evaluation include the stalk nitrate test, the chlorophyll at harvest test, and the end-of-season soil nitrate test. The stalk nitrate test showed a wide range of values with a clear trend appearing at all but one site. Lawrence says stalk N values increased as sidedress rates increased. None of the non-responsive second-year corn sites showed a sufficient level of N at the no sidedress rate based on interpretations currently used elsewhere, suggesting the need to develop NY-specific critical range data.

The chlorophyll test at harvest time for the Northern NY sites showed low levels for the two responsive second-year corn sites. An impact of N addition on chlorophyll in ear leaves was seen in the other sites but for the non-responsive sites values at 0 N were high indicating that N was not limiting.

For more information on the Northern New York Agricultural Development Program, go online to www.nnyagdev.org.   # # #