Nitrogen holds the first rank among all essential nutrients applied to the crops worldwide. The invention of synthetic Nitrogen fertilizer over a century back (early 1900s) led to dramatic increase in grain yields and global green-revolution. Yet after a >100 years of progress we haven’t attained the level of 50% global nitrogen use efficiency. I cannot think of any other operation or process in agricultural industry that tolerates 50% or lower efficiency rates. We have long ways to go in achieving 5-R Precision Stewardship. What would it take? Can data-driven nitrogen management be the solution? This presentation will provide a holistic approach to Past, Present, and the Future of Nitrogen management.

Crop nitrogen need is directly related to yield potential and increases with higher production.  Spatial variation in crop yield across fields is well known and new technologies that allow on-the-go changes to plant population and even hybrid provide the best opportunity yet to optimize inputs.  However changes in plant population also affect nutrient need.  Discussions will focus on how the use of sub-field management changes, such as variable population, affect nitrogen needs and dynamics.  Pros and cons of various N management strategies in response to other sub-field management decisions will also be covered. 

Nitrogen management: Using site-specific strategies to balance agronomic and environmental goals of winter wheat production in the inland Pacific Northwest

Fertilizer management is challenging in the inland Pacific Northwest USA because of its rolling landscape and variable climate. Winter wheat yield goals vary greatly within and across fields, and so a one-size-fits-all approach to nitrogen fertilizer management is inefficient. Site-specific fertilization strategies are needed to match nitrogen supply with variable crop demand. Like elsewhere, the region has adopted a three-pronged approach that involves (1) the implementation of precision agriculture technologies, (2) the utilization of spatial soil, terrain, and crop data to predict crop performance, and (3) the evaluation of site-specific practices. This presentation will feature the regional application of remote sensing and other technologies to collect georeferenced crop and soil data, which is then used to assess crop performance and create site-specific fertilizer management plans. The presentation will also highlight evaluation tools being developed to establish nitrogen use efficiency thresholds for meeting agronomic and environmental goals. 

This talk was prepared with co-authors: Dave Brown (Washington State University) and Erin Brooks (University of Idaho)