The short term effects of manure and compost application on soil nitrogen have been extensively studied. However, there is little long term data from repeated applications of manure and compost on soil nitrogen. This study was started in central Pennsylvania in 1995 to evaluate N availability coefficients for dairy and poultry manure and to determine the N availability coefficients for composts made from these same manures. Dairy and poultry manure, and composts made from these manures were applied at equivalent total N rates (approximately 245 kg/ha for dairy and 156 kg/ha for poultry) and a complete N fertilizer response curve was also included. During the initial study profile soil samples were collected for nitrate analysis. Following the completion of the initial study the same manure, compost and fertilizer treatments were continued in the same plots for a total of 10 years. In the fall of 2004 the plots were again deep sampled for nitrate analysis. During the 10 years the manure treatments resulted in higher average corn grain yields than the compost treatments even though the same total N was applied, indicating lower N availability from the compost than the manure, as would be expected. Total soil N to 1 meter depth indicated higher recovery of applied N in the compost treatments than the manure or equivalent fertilizer treatments. Early on the fertilizer treatments and, to a lesser extent, the manure treatments showed higher levels of nitrate throughout the sampled soil profile. However, soil nitrate levels were very low at the end of the 10 years for all treatments and there was very little difference in the pattern of soil nitrate through the sampling depth.