1. Agriculture and Agri-Food Canada; Swift Current SK S9H 3X2 Canada
2. USDA-ARS; Southern Regional Research Center; New Orleans LA 70124
3. Dep. of Plant and Soil Sciences; Oklahoma State Univ.; Stillwater OK 74078
4. USDA-ARS; Southeast Watershed Research Lab.; Tifton GA 31793
5. USDA-ARS; Sustainable Agricultural Systems Lab.; Animal and Natural Resources Institute; Beltsville MD 20705
6. Stanford Magnetic Resonance Lab.; Stanford Univ.; Stanford CA 94305