Compacta？？o superficial de Latossolos sob integra？？o lavoura: pecuária de leite no noroeste do Rio Grande do Sul

in crop and livestock integration system, pressure applied by animal trampling and farm-machinery wheeling changes soil structure. in this study soil bulk density, porosity and soil penetration resistance were evaluated in five farms which adopt the crop and livestock integration system. the results indicated an increase in soil compaction by cattle trampling in the surface soil layer (0.10m). the bulk density was above 1.4mg m-3, the porosity is below 0,10m3m-3 and soil penetration resistance is above 2mpa at 0.26kg kg-1 soil moisture, which characterize soil physical degradation. thus, adoption of management practices suitable for the soil physical amelioration and prevent further increase in the state of compaction is necessary.