Physical characteristics of a Dark-Red Latosol under different soil management

Abstract

During four years, a trial on a clayey Dark-Red Latosol to compare conventional tillage with direct drilling, under three crop rotations, was carried out in the Mid-Southern region of Paraná, Brazil. The crop rotations were: continuous soybeans and wheat, continuous maize and wheat, and soybeans alternated yearly with maize in rotation with wheat. Measurements were made at the end of the fourth year of the summer crops at 10 to 30 cm of depth. Direct drilling significantly increased the soil bulk density and microporosity whereas it decreased the soil total porosity and macroporosity at 10 cm depth. There were no Statistical differences at 30 cm of depth. In the 0 to 20 cm top layer, direct drilling was beneficial for the aggregate stability. Differences among crop rotations for these parameters were not observed. Infiltration rates under conventional tillage were higher than in direct drilling and were the highest where maize crop was grown, specially under conventional tillage. Infiltration data were fitted according to Kostiakov's model.