Infiltration and  runoff  from  mechanically  treated  arid South­ western rangeland  were measured. Control plots dominated by creosotebush  had greater infiltration rates than the 1972 and 1976 rootplowed  and  seeded  treatments, stressing  the  importance of cover for reducing runoff and controlling erosion.Infiltration rates on dry soils were significantly higher on the 1972 rootplowed and seeded treatment compared  with the 1976 rootplowed  and seeded treatment,  indicating   the  lack   of  soil  structure  in  the  1976 treatment.