1. Dep. of Crop, Soil, and Environmental Sciences; Univ. of Arkansas; Fayetteville AR 72701
2. Dep. of Soil Science; North Dakota State Univ.; P O Box 6050 Fargo ND 58108-6050
3. Texas Commission on Environmental Quality; P.O. Box 13087 Austin TX 78711-3087
4. Agricultural Statistics Lab.; Univ. of Arkansas; Fayetteville AR 72701
5. Dep. of Biological Sciences; Univ. of Arkansas; Fayetteville AR 72701