Efeitos de manejo e rotação de culturas em atributos físicos do solo ; Effects of soil tillage and crop rotation systems on soil physical attributes

The objective of this study was to evaluate the effects of soil tillage and crop rotation systems on soil physical attributes. The experiment was conducted for five consecutive years and ten crop seasons in a dystrophic Oxisol in Santo Antônio de Goiás, Goiás State, Brazil, in a completely randomized design with four replications arranged in a 2 x 4 factorial split plot. Tillage systems were assigned to plots: (P1) no-tillage followed by plowing and (P2) continuous no-tillage; and crop rotations were assigned to subplots: (R1) millet - common bean - millet - common bean - rice - common bean - millet - common bean - millet - common bean, (R2) millet - common bean - soybean - common bean - rice - common bean - millet - common bean - corn - common bean, (R3) millet - common bean - millet - common bean - rice - common bean - corn - common bean, and (R4) soybean - common bean - corn - common bean - rice - common bean - soybean - common bean - corn - common bean. Tillage and crop rotation systems affected soil bulk density, macroporosity, and total porosity. Continuous no-tillage increased soil bulk density and decreased soil macroporosity and total porosity. Soil organic matter content was inversely correlated to soil bulk density and directly correlated to soil macroporosity. ; UFG ; O objetivo deste trabalho foi estudar os efeitos de dois sistemas de manejo do solo e quatro rotações de culturas sobre atributos físicos do solo. O experimento foi conduzido por cinco anos consecutivos, durante os quais se efetuaram dez cultivos, em um Latossolo Vermelho distrófico, em Santo Antônio de Goiás, GO. Utilizou-se o delineamento inteiramente casualizado, com quatro repetições e esquema fatorial 2 x 4, em parcelas subdivididas. As parcelas foram constituídas pelos sistemas de manejo: (P1) plantio direto seguido anualmente de um preparo com arado e (P2) plantio direto contínuo; e as subparcelas, pelas rotações: (R1) milheto - feijão - milheto - feijão - arroz - feijão - milheto - feijão - milheto - feijão; (R2) milheto - ...