1. Dep. of Soil Science Federal Univ. of Santa Maria (UFSM) Santa Maria RS Brazil
2. Dep. of Crop and Soil Sciences NC State Univ. Raleigh NC USA
3. Dep. of Zootechnics SC State Univ. (UDESC) Chapecó SC Brazil
4. Dep. of Agriculture, Biodiversity and Forest Federal Univ. of SC (UFSC) Curitibanos SC Brazil
5. Dep. of Soil Science and Natural Resources SC State Univ. (UDESC) Lages SC Brazil