The MRTN Approach to Making Nitrogen Rate Recommendations: Background and Implementation
Emerson D. Nafziger, John E. Sawyer, Carrie A. M. Laboski, David W. Franzen
Abstract
Based on a seminal paper published by Stanford in 1973, many land grant universities adopted N rate guidelines that used expected yield times a factor (such as 1.2 lb N/bu), with adjustments for previous crop, to formulate N rate recommendations for corn. However, discrepancies between yield‐based N rate recommendations and recent N response data led to the development of an empirical approach, using N response data to generate optimum N rates. The idea of combining crop N response data, dubbed the Maximum Return to Nitrogen (MRTN) approach, was initiated in the mid‐2000s and is today used in seven Corn Belt states. Earn 1.5 CEUs in Nutrient Management by taking the quiz for the article at https://bit.ly/35Fy683 . View all CEUs at https://web.sciencesocieties.org/Learning‐Center/Courses .