Presentations
T8
Nutrient Management
Tue, Dec 18, 2018
8:00am to 8:50am
T1
Nutrient Management
Tue, Dec 18, 2018
1:00pm to 1:50pm
Determination of Optimum N Rates for Corn: Models Versus Reality
Prediction of the optimum N-rate for corn is complex as it involves weather, genetics, soils and management factors. Many crop-based and/or soil-based tools exist to provide N rate predictions that range from empirical (easy to use and understand) to mechanistic (complex to use and understand). Although there is no consensus on which tool is the best, there is a clear consensus that we need to further improve the accuracy of the tools. Mechanistic simulation models have the potential to provide scenarios in addition to N-rate predictions but these models are currently viewed as “black boxes”. In this presentation, I will open the “black box” and I will describe the science behind it and provide examples of pre-plant and in-season predictions of optimum N rates. Prediction accuracy, pros and cons of using modeling, and needs for improved predictions will be discussed. Finally, a new approach to predict N-rates for corn that is based on statistical modeling will be presented.
Speaker
Sotirios Archontoulis
Sotirios Archontoulis is a professor of integrated cropping systems at the Department of Agronomy, Iowa State University. His research aims to predict impacts (e.g. climate change), explain causes (e.g. high/low yields), and design future strategies to improve crop productivity and environmental sustainability. His approach combines field experimentation with process-based simulation models to understand Genotype x Environment x Management interactions and enable prediction at scale.