1. Auburn Univ. Agronomy and Soils 411 S. Donahue Dr. Auburn AL 36832‐5806
2. Univ. of Wisconsin‐Madison Dep. of Soil Science 1525 Observatory Dr. Madison WI 53706
3. USDA‐ARS 411 S. Donahue Dr. Auburn AL 36832
4. Auburn Univ. Agronomy and Soils 204 Ext. Hall Auburn AL 36849