Erosividade da chuva e erodibilidade de Cambissolo e Latossolo na região de Lavras, sul de Minas Gerais

Abstract

Relatively few studies in Brazil have investigated soil erodibility, mainly for Cambisols (Inceptisols), due to the tediousness of data collection in natural rainfall experiments. Knowledge about erodibility and erosivity is important for conservation planning, which contributes to soil sustainability. This study aimed at evaluating the rainfall erosivity and erodibility of a typic dystrophic Tb Haplic Cambisol (Inceptisol) and a typic dystroferric Red Latosol (Oxisol) under natural rainfall, in Lavras, state of Minas Gerais, Brazil, between 1998 and 2002. Pluvial precipitation data were obtained from the main weather station of Lavras, of the Universidade Federal de Lavras, close to the soil loss experimental plots. Erosivity (EI30) was calculated as the product of the rain kinetic energy by the maximum intensity in 30 min. Based on these data, correlated with the soil losses, the soil erodibility could be computed. The mean annual total precipitation was 1,287 mm and the mean calculated erosivity 4,865 MJ mm ha-1 h-1 year-1. The erodibility of the Cambisol was 0.026 Mg h MJ-1 mm -1 and of the Latosol 0.004 Mg h MJ-1 mm -1, in agreement with their differential mineralogical, chemical, physical and morphological properties.