Submitted to: Maryland Water Monitoring Council Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 11/24/2003
Publication Date: 11/28/2003
Citation: Meisinger, J.J. 2003. Principles for managing agricultural nitrogen. Maryland Water Monitoring Council Annual Meeting.
Technical Abstract: Managing agricultural nitrogen (N) to minimize N losses is a challenge to nutrient managers who must develop nutrient management plans that consider rate and application strategies that account for hydrology, soil properties, and crop-tillage systems of a specific site. Ammonia losses are becoming a renewed concern, which can be managed by soil incorporation. Nitrogen leaching is a significant loss, with leaching events occurring when soil nitrate concentrations are high and water is moving through the soil profile. The universal tools for managing N leaching include understanding the soil-crop-hydrologic cycle because hydrology drives N losses, avoiding excess N applications because excess N is most vulnerable to loss, and applying N in-phase with crop demand because this increases crop N recoveries. Cropping system tools for managing leaching include use of grass cover crops, and adding a legume or deep-rooted crop to a rotation. Other approaches include use of riparian zones and conservation reserve program areas. Site monitoring tools such as the pre-sidedress soil nitrate test, and the leaf chlorophyll meter are useful in identifying N sufficient sites and avoiding excess N rates. Real-time monitoring techniques, combined with variable rate N applicators, offer new opportunities for improving N management. The application of the above N management tools to fields, or specific management areas within a field, will improve crop N recoveries with subsequent reductions in N losses to the environment.