The objective of this work was to evaluate the soil physical properties and the yield of flooded rice under no-tillage, in the west border of Rio Grande do Sul, Brazil, compared with the conventional tillage system. The experimental design was completely randomized, with three experiments (E) and ten replicates: E1, no-tillage after leveling (E1PDR) and conventional tillage with two harrowings at 0.0-0.07 m layer after leveling (E1C), after seven years of fallow of rice tillage, with sowing of rye grass in winter and grazing; E2, no-tillage (E2PD) and conventional tillage (E2C), after native field; E3, no-tillage (E3PD), no-tillage after leveling (E3PDR), and conventional tillage (E3C) after rice under conventional tillage, during one year under native field. The soil physical properties differed little between the no-tillage system and conventional tillage. Continued tillage with irrigated rice caused soil compaction in the 0.07-0.10 m layers. The rice yield did not differ between the no-tillage system and conventional tillage, in the experiments 1 and 2. In experiment 3, with greater amount of remaining rice straw, the yield was greater in the conventional tillage system
Oryza sativa; soil tillage; soil physical quality
