The presidedress nitrate test (PSNT) is currently the best tool available for New York (NY) producers to determine if corn (Zea mays L.) will benefit from sidedress N. The PSNT requires 0-30 cm soil samples which can be difficult on stony NY soils and samples need to be taken in late-spring, an inopportune time for dairy farmers. The Illinois soil N test (ISNT) is a simple test that estimates exchangeable NH₄-N and amino sugar-N and shows promise as a tool for identifying sites that are nonresponsive to sidedress N fertilization in Illinois. Field trials were conducted in NY to (1) study the effects of dairy manure and compost amendments on the ISNT and (2) determine the accuracy of the ISNT in predicting sites that are nonresponsive to N in NY. Results from a four year field trial (2001 to 2005) in central NY show that increases in ISNT levels over time were consistent with estimated N credits for previously applied manure and compost amendments. Results from 33 field trials over three years (2002 to 2004) throughout NY indicate that the ISNT was effective in separating responsive from nonresponsive sites if organic matter was considered as well.