Soil structure modifications caused by different tillage systems can result in larger or smaller compaction, which can interfere in the mechanical resistance to penetration, bulk density and soil porosity, influencing root growth and productivity of the crops. The objective of this work was to evaluate the effect of compaction of an Oxisol, located in Jaboticabal, São Paulo State, Brasil, caused by traffic of machinery, on soil physical properties, least limiting water range (LLWR), aerial growth and corn productivity. The experimental design used was a completely randomized with six compaction levels and four repetitions. Undeformed soil samples were collected in the layers of 0.02-0.05, 0.08-0.11 and 0.15-0.18 m, to determinate soil resistance to penetration, porosity, bulk density and LLWR. Corn plant characteristics evaluated were: plant height, ear height, stem diameter, ear number per plant, plant dry mass, mass of 1,000 grains and grains yield. Data were submitted to variance analysis and when significant, regressions were adjusted between resistance to penetration and bulk density and plant characteristics. The range of water content established by LLWR where there would not be restrictions for corn development decreased with the increase of compaction until the limit of Ds of 1,46 Mg m-3. Compaction restricted all evaluated characteristics of the crop, with exception only for number ear of per plant.
Zea mays; soil physical quality; bulk density; resistance to penetration
