Silage Corn Response to Urea and Controlled Release Urea in till and No-till.

Methods are needed to enhance performance of widely used urea fertilizer. In British Columbia, silage corn is fertilized with urea by either broadcasting before seeding or sidedressing at 9 leaves. This 3-yr experiment in coastal BC, Canada evaluated response of silage corn to standard and controlled release urea (CRU= Nutrisphere® by Simplot) applied at 160 kg N ha^-1 by broadcasting or side-dressing (placing below the soil surface 15cm from plants) and to CRU applied by side-banding at planting time. A preliminary trial demonstrated crop injury from side-banded urea. The CRU was side-banded at 10 or 15 cm from the seed row and by side-banding half the CRU (10 cm) and sideressing half. The corn was grown by conventional till (CT) and no-till (NT). Averaged across tillage, whole crop and grain yields were greater for broadcasting than sidedressing while N uptake was better for sidedressing, with little difference between N forms. Whole crop yield, grain yield and N uptake were generally better with side-banding than conventional methods of application, and the split side-banding/side-dressing method tended to be somewhat better than the others. The benefits of side-banded CRU were more pronounced for NT than CT. These results suggest that the effectiveness of urea-N can be improved by side-banding CRU.