The objective of this study was to evaluate the immediate and the residual effects of soil preparation on bulk density, aeration porosity and root development relationships in stabilized structural layers of a typic Haplorthox soil due to long-term no-tillage system of corn (Zea mays L.).The immediate effects of soil preparation to planting involving subsoiling, plowing, and disking improved soil macroporosity and root development for a short period of time. In these treatments and on the first three consecutive years, the adoption of continuous no-tillage management decreased soil macroporosity and root development. The long-term benefits of continuous no-tillage on soil macroporosity initiated at the fourth agricultural year. From there on these values increased and had returned to corresponding levels of immediate effects of mechanical tillage performed in the experimental area at the eighth consecutive agricultural year. The relationships between root development, bulk density and macroporosity were established by equations and as a range of root development classes.
Zea mays; porosity; soil structure; no-tillage
