Soil physical characteristics were evaluated, after eight years (1995 to 2003), on a typic Hapludox located in Coxilha, Rio Grande do Sul State, Brazil. Six crop production systems were evaluated: system I (wheat-soybean / black oat + common vetch pasture-corn); system II (wheat-soybean / black oat + common vetch + annual ryegrass pasture-corn); system III (wheat-soybean / black oat + common vetch pasture-pearl millet pasture); system IV (wheat-soybean / black oat + common vetch + annual ryegrass pasture-pearl millet pasture); system V (wheat-soybean, white oat-soybean / black oat + common vetch pasture-pearl millet pasture); and system VI (wheat-soybean / white oat-soybean / black oat + common vetch + annual ryegrass pasture-pearl millet pasture). Soil bulk density and resistance to penetration increased from deeper layer (10-15 cm) to top layer (0-5 cm). In the systems I, V and VI, total porosity decreased and soil bulk density resistance to penetration increased from the deeper layers to top layer surface, due to higher intensity of livestock activities. After eight years of use, the production systems under no-till, involving annual winter and summer pastures and crops, did not promoted soil degradation, in constraining levels, on soil physical attributes.
lay farming; soil bulk density; soil porosity
