Long-term Optimum Nitrogen Rate for Corn Yield and Soil Organic Matter

Decisions on optimum N rates are often made on the basis of single-year responses. Data are limited on the long-term impact on productivity and soil organic matter of rates higher or lower than these short-term optima. This controlled experiment was designed as a base for testing the application of dynamic soil-crop-atmosphere models as predictors of N rates for corn that optimize sustainability. The specific objectives include: (1) assessment of short and long-term effects of N on productivity, environmental impact, profitability, and cropping system sustainability; and (2) validation of crop models, such as Hybrid Maize, for simulating yield potential, seasonal growth and yield, and fertilizer N management requirements.

The project began with a uniformity trial conducted in 2008 at Elora, Ontario. Long-term and short-term N rate treatments commence in 2009. ON-29