Abstract

Changes to soil use can modify the soil’s physical and hydraulic properties, affecting its potential for productivity. This study aimed to characterize the physical and hydraulic properties of a clayey Dystroferric Red Latosol under the following land uses: conventional tillage (CT), direct drilling systems (DD), and native forest (NF). The study was conducted in Londrina (PR), Brazil, (23°23′ S, 50°11′ W and altitude of 585 m). Soil samples were collected at depths of 0 to 0.10, 0.10 to 0.20, 0.20 to 0.30, and 0.30 to 0.40 m. The following properties were evaluated: size distribution of solid particles, particle density, soil bulk density, total porosity, macroporosity, microporosity, water infiltration, and soil water retention curve. Conventional tillage and DD of this land modified soil physical and hydraulic properties from that under NF. The NF soil had greater organic matter content in its surface layer, a greater number of macropores, lower density, and less water retention capacity than soils from the CT and DD systems. At a precipitation rate of 70 mm h^-1, only the CT system exhibited surface run-off. This was due to rupturing of the porous system and a lower infiltration rate. In contrast, plant residues in the DD system protected the soil structure against damage caused by direct impact due to raindrops, allowing for total infiltration of simulated rainfall events. The NF soil is important in extracting and replenishing groundwater stores. However, it does not retain more water than the other systems in the surface layers.

Key words: Soil water retention, soil water infiltration, direct drilling system, Dystroferric Red Latosols, conventional tillage.