1. Dep. of Soil Science North Carolina State Univ. 207 Research Stn. Rd. Plymouth NC 27692
2. Dep. of Soil Science North Carolina State Univ. 455 Research Drive Mills River NC 28759
3. NCDA & CS Agronomic Services Div. 4300 Reedy Creek Road Raleigh NC 27607‐6465
4. Dep. of Crop Science 207 Research Stn. Rd. Plymouth NC 27692