Medium-Term No-Tillage, Additional Compaction, and Chiseling as Affecting Clayey Subtropical Soil Physical Properties and Yield of Corn, Soybean and Wheat Crops

Understanding the soil-plant relationship is important to determine critical limits of soil properties that influence crop growth and yield. The objectives were quantify compaction levels on physical yield in a clayey Oxisol. An experiment was performed having main plots, (NT: no-tillage during six years, NTC: NT + four passes 10 Mg machine agricultural year 2003/2004, Chisel: chiseling harrowing 2003/2004), sub-plots, summer crops soybean corn, wheat winter season. We measured mechanical properties, along with wheat, root last two crops. After machine, resistance penetration increased 0.12 m depth, while Chisel disrupted 0–0.20 layer, effects persisting for at least nine months. Soil concentrated 0.05–0.15 layer. Corn similar among treatments, highest NT, sequence under NT.