The Universal Soil Loss Equation (USLE) factors were determined in a Haplargs under natural rainfall conditions. Data concerning to the years of 1983 -1990 were obtained at the Sumé Experimental Station (Paraíba State - Brazil) of the Federal University of Paraíba (UFPB). The treatments consisted of runoff plots with bare soil, native semiarid vegetation runoff plot, mulch runoff plot, palm leaf under downhill runoff plot and under contour palm leaf runoff plot. The annual average of the rainfall erosivity factors EI30 and PI30 were 4,928 MJ mm ha-1 h-1 and 19,734 mm-2 h-1, respectively. The calculated annual mean values of the erodibility parameters were calculated in 0.013 t h MJ-1 mm-1 and 0.003 t h ha-1 mm-2. The calculated values for the support practice factor cropping-management parameter were 0.0015, 0.0174, 0.0133, 0.0056, 0.5103 and 0.2355 for the native semiarid vegetation runoff plot, native semiarid vegetation (new) runoff plot, mulch runoff plots, downhill palm leaf runoff plot and contouring cropped palm leaf runoff plot treatments, respectively. The values of the support conservationist practice factor to downhill palm leaf runoff plot was 0.46.
erosivity; erodibility; erosion
