Department of Agronomy, Iowa State University, Agronomy Hall, Ames, IA, USA. andreasa@iastate.edu|Department of Agronomy, Iowa State University, Agronomy Hall, Ames, IA, USA. andreasa@iastate.edu|Department of Agronomy, Iowa State University, Agronomy Hall, Ames, IA, USA. andreasa@iastate.edu|Department of Agronomy, Iowa State University, Agronomy Hall, Ames, IA, USA. andreasa@iastate.edu