After early-season N fertilizer applications, uncontrollable factors such as excessive rainfall may produce soil conditions conducive to inefficient plant N uptake and/or fertilizer N loss through denitrification. Field experiments were conducted in 2005 on Commerce silt loam and Sharkey clay at the Northeast Research Station near St. Joseph, LA to determine the influence of late N applications on corn yield. Nitrogen as 32% URAN was knifed-in with a variable rate applicator at the three-leaf growth stage at rates of 120 and 180 lb N/acre on Commerce silt loam and 180, 210, and 240 lb N/acre on Sharkey clay. Late N fertilizer rates of 0, 30, and 60 lb N/acre as ammonium nitrate were broadcast by hand at tassel emergence on both soils. Pioneer brand 32D99 was planted April 10 at approximately 30,000 seed/acre.The Commerce trial was dryland and the Sharkey trial irrigated. Rainfall was about normal in April, May, and July and below normal in June. On Commerce silt loam, late N applications increased yield by approximately 14 and 22% for the 120 and 180 lb N/acre early-season rates, respectively. Yield response to late N on Sharkey clay was much less than Commerce trial, with yield responses ranging only from 4 to 7% across early-season N rates. Plant measurements, including chlorophyll readings (SPAD meter) and leaf-N will be discussed.