1. Dep. of Agricultural & Biological Engineering Mississippi State University Starkville MS 39762 USA
2. Dep. of Biological Systems Engineering Univ. of Nebraska‐Lincoln Chase Hall, East Campus Lincoln NE 68583 USA
3. Woodwell Climate Research Center 149 Woods Hole Road Falmouth MA 02540 USA
4. NRCS‐SPSD‐NSSC Kellogg Soil Survey Laboratory Lincoln NE 68508 USA