1. Dep. of Agronomy & Horticulture Univ. of Nebraska‐Lincoln 1875 N 38th St, 279 Plant Sciences Hall, PO Box 830915 Lincoln NE 68583‐0915 USA
2. Nebraska Water Center, part of the Robert B. Daugherty Water for Food Global Institute, 109 Water Sciences Laboratory Univ. of Nebraska Lincoln NE 68583‐0844 USA
3. USDA‐ARS Agroecosystem Management Research Unit 251 Filley Hall, East Campus Lincoln NE 68583‐0937 USA