Soil physical attributes and agronomic characteristics relationships of soybean in no-tillage

The objective of this work was to evaluate the soil physical attributes and their relationship to soybean productivity under no-tillage system. The study was conducted in a Oxisol, based on randomized blocks design, with the treatments: no-tillage for 10 years (0 tractor traffic) and five tractor-traffic intensities (2, 4, 6, 8, and 12 passes), with five repetitions. An increase of macroporosity up to 10% under soil bulk density ranging from 1.51 to 1.56 mg.m-3 and soil penetration resistance between 1.5 to 2.0 MPa, on the 0.00-0.10 m layer benefited the soybean productivity. The number of pods per plant, grain number per plant, stem diameter, and soybean productivity is higher in Oxisol, under intermediate compression. Soil bulk density and soil penetration resistance showed to be sensitive an indicators of soil physical quality, with more relation to soybean grain productivity.