Kentucky bluegrass post-harvest residue in northern Idaho historically has been burned to maintain stand life and profitability. Alternatives to open field burning are necessary to address adverse impacts of burning on air quality. Little is known about the effects of current non-thermal management systems on in-situ decomposition and nitrogen cycling, two factors may impact the success of these systems. The impact of residue management on decomposition, nitrogen inputs, and losses was evaluated within replicated full-load burn (FLB), bale-burn (BB), and bale-mow-harrow (BMH) plots established in Kootenai County, ID in 2001. Standing and non-standing residue was measured monthly from July 2003 to July 2004. Decomposition of non-standing residue (thatch) from October 2003 to May 2004 ranged from 75% in BMH plots to 86% in the BB plots. Although more decomposition occurred in the BMH plots, this treatment also had more non-standing residue (0.83 Mg ha^-1) in the spring sampling as compared to FLB (0.19 Mg ha^-1) and BB (0.18 Mg ha^-1) treatments. Based on measurements of chemical composition and weight loss, decomposition of thatch over the winter resulted in the return of 9.7 kg N ha^-1 in the FLB, 12.9 kg N ha^-1 in the BB, and 33.8 kg N ha^-1 in the BMH treatments. Mean nitrate concentrations from lysimeters 50 cm deep ranged from 21.3 mg NO₃^--N L^-1 in BB plots to 17.6 NO₃^--N L^-1 in BMH. It appears that burning enhances thatch decomposition (FLB, BB) over winter compared to non-burn plots (BMH). Full-load-burn, BB, and BMH appear to have no significant impacts on lysimeter nitrate concentrations.