Produtividade de grãos de arroz irrigado por inundação em diferentes quantidades de palha residual e sistemas de manejo

Abstract

The Rio Grande do Sul State is the greater producer of flooded rice from Brazil highlighting the west border region. The objective of this work was to evaluate soil flooded rice yield with different levels and tillage system. The work was carried out in the harvest 2010/2011 season with experimental design completely randomized with four experiments (E) with ten replicates in experiment 1, 2 and 3 and, six replicates in experiment 4. The experiments and treatments were: E1, no-tillage (E1PD) and conventional tillage with two harrowings at 0.0-7 cm layer after leveling (E1C), in area of one year of rice culture 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 filed; E3, no-tillage (E3PD), and conventional tillage (E3C) after rice under no-tillage, during two year under native field; E4, four levels of remaining rice straw (0; 8,196; 16,392 and 24,588 kg ha-¹) before sowing. It was evaluated rice dry mass, panicula number, rice yield in 2 m². The flooded rice yield no differ between no-tillage and conventional tillage system. The remaining rice straw not influence flooded rice yield in no-tillage system.