Dairy farmers in the northeast face challenges in the application of manure in fall and on-time planting of cool-season grasses to maximize recovery of residual N and nutrients released from fall applied manure. On-time planting of cover crops can reduce ammonia volatilization from fall, surface-applied manure, and prevents N loss to leaching. This study aimed to investigate a management strategy for mitigating ammonia volatilization from slurry manure applied to the growing cover crops planted at different dates.