The adoption of no-tillage system, with the inclusion of grass species of high C/N relationship, can minimize the structural degradation of the soil. The objective of this research was to evaluate the influence of including Brachiaria in crop rotation systems on the physical-hydric properties and the organic matter content in a Dystrophic Oxisol under no-tillage. The experiment was conducted in a randomized block design, in split plots, with four replications. The plots were composed by four systems of crop rotation and the subplots by four sampling depths (0-10; 10-20; 20-40, and 40-60 cm). The crops were: rice (R); irrigated dry bean (DB); corn (C); soybean (S); rice (R+B), corn (C+B), and soybean (S+B) intercropped with Brachiaria. The crop rotation systems were: S1 - R/DB/C/DB/S/DB; S2 - R+B/DB/C+B/DB/S+B/DB; S3 - C/DB/S/DB/S/DB; and S4 - C+B/DB/S+B/DB/S+B/DB. It was considered a native forest, located at 500 m from the experiment, as reference. The inclusion of Brachiaria in crop rotation systems did not affect soil bulk density, macroporosity, and available soil water capacity. Total soil porosity and organic matter content of the soil were favored in the crop rotations that included more number of soybean cultivations. The association of soybean with Brachiaria contributed to the stability of the aggregates and the summer grasses with Brachiaria to reduce the soil resistance to penetration.
soil bulk density; soil porosity; soil aggregation
