Effects of Previous Crop and Corn Planting Date On Corn Response to Nitrogen Fertilizer.

Corn nitrogen management is affected by previous crop, but little is known about the effects of corn planting date after previous crops of corn, soybean and wheat:soybean double-crop. Corn was planted after each crop above in mid-April, early May and late May at two locations in Illinois. Nitrogen rates of 0, 67, 134, 202 and 269 kg per ha were applied side-dress injected to corn at each planting date x previous crop combination. Differences in optimum economic nitrogen rate and nitrogen use efficiency were observed.