Corn producvtion in the Mississiippi Delta Region of Arkansas Ahas significantly inctreased in recent years.  Improving nitrogen use efficiency throuh improved N fertility management practices will increase the growers' profit margin and reduce the risk of potential contamination of water resources.  Replicated field studies were conducted at 20 representative site in MDRA to evaluate the effect of sidedress application of N on corn grain yield and N concentration and leaf N concentration.  N fertilizer was applied in split application at rates of 0-336 kg/ha (at 56 kg N/ha intervals).  The 1st 22 kg/ha of N was applied at or before planting and the balance of N was appllied at V6 stage. Leaf samples were collected at early silk stage and analyzed for total N. Grain yields were measured at harvest and grain total N was measured.     The data will be used to evaluate the relation between Sidedress N application rates and corn grain yields and grain N content, and corn leaf tissue N. The information will from this and future studies will be used to refine the current corn fertility recommendation in MDRA.