Submitted to: Agronomy Abstracts
Publication Type: Abstract only
Publication Acceptance Date: 8/1/2005
Publication Date: 11/1/2005
Citation: Raun, W., Schepers, J.S. 2005. What new equipment is available to improve n-use efficiency. Agronomy Abstracts. Interpretive Summary:
Technical Abstract: Significant increases in nitrogen use efficiency (NUE) have taken place over the past 10 years using precision agricultural management practices. However, substantial increases are needed to improve upon world NUE that still hovers near 33 percent. Before issues of NUE can be addressed, soil pH, EC, and other macro and micronutrient deficiencies need to be addressed first. Leibig's law of the minimum holds true today whereby the nutrient present in the least relative amount is the limiting nutrient. Equipment that will help improve nitrogen management for cereal crops includes the use of hand-held active sensors, aerial photography, satellite imagery, and virtually any other approaches that will assist in managing the variability present in producer fields. Various products from Capstan will assist in delivering more accurate rates of liquid and gaseous forms of N. VERIS pH probes and EC mapping devices will also assist in monitoring field variability. The simplest and most significant improvement for mid-season N management has come via the use of N reference strips or N rich strips first promoted by the USDA-ARS group in Nebraska. Using a reference strip, mid-season fertilizer N rates can be adjusted using highly sensitive sensors that detect the differences between it and the farmer practice. Sufficiency concepts and yield prediction combined with response indices are currently being tested around the world in regional trials organized by scientists in Nebraska, Missouri and Oklahoma. This collaborative effort will lead both to the identification of the equipment, and/or approaches to be used for improving NUE, and the functional biological algorithms that should be employed.