1. Department of Agronomy, State University of Maringá, Maringá, Brazil
2. Department of Soil Science, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
3. Department of Field Crops, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
4. Department of Agronomic Science, Federal University of Technology – Paraná, Francisco Beltrão, Brazil
5. Department of Soil Science, Federal University of Santa Maria, Santa Maria, Brazil