Legume/grass cover crop mixtures and sidedress subsurface band manure application are two approaches to improving nitrogen (N) use efficiency in a cover crop-based no-till corn (Zea mays L.) system. The objectives of this study were to: 1) quantify cover crop biomass and N content in response to different hairy vetch (Vicia villosa Roth)/cereal rye (Secale cereale L.) sown proportions, 2) evaluate the effects of cover crop species proportions and pelletized poultry litter (PPL) application method on residue decomposition, and 3) model the spatio-temporal dynamics of soil inorganic N as influenced by different cover crop residues and subsurface band-applied PPL. Results suggest that cover crop mixtures can accumulate as much biomass as a cereal rye monoculture and as much N as a hairy vetch monoculture, and have decomposition patterns intermediate between those of monocultures. Subsurface band PPL application provided a localized N source that did not influence decomposition of surface mulches.