SUMMARY Soil management including crop rotation and tillage may affect soil structure in a short and long time range. Low soil structure stability is closed related to water erosion. The objectives of this study were to measure the effect of tillage and clay content on aggregate stability at com seeding, flowering and harvesting. This work was carried out in a Typic Hapludalf (Red-Yellow Podzolic) under oat + vetch/corn production system. Temporal variation of aggregate stability was observed for systems and for places with different clay contents. The geometric mean diameter of no-tillage treatment were 2.1 to 3.8 times greater than those for one time conventional tillage. This behavior was attributed to organic residues cover, microbiological activity and no soil mobilization.
Temporal variation; structural stability; soil tillage; clay content
