Revista Brasileira de Ciência do Solo
On-line version ISSN 1806-9657
CASTILHO, Selene Cristina de Pierri; COOPER, Miguel and JUHASZ, Carlos Eduardo Pinto. Influence of crust formation under natural rain on physical attributes of soils with different textures. Rev. Bras. Ciênc. Solo [online]. 2011, vol.35, n.6, pp.1893-1905. ISSN 1806-9657. http://dx.doi.org/10.1590/S0100-06832011000600006.
One of the main negative anthropic effects on soil is the formation of crusts, resulting in soil degradation. This process of physical origin reduces soil water infiltration, causing increased runoff and consequently soil losses, water erosion and/or soil degradation. The study and monitoring of soil crusts is important for soil management and conservation, mainly in tropical regions where research is insufficient to explain how soil crusts are formed and how they evolve. The purpose of this study was to monitor these processes on soils with different particle size distributions. Soil crusts on a sandy/sandy loam Argissolo Vermelho-Amarelo (Typic Hapludult), sandy loam Latossolo Vermelho-Amarelo (Typic Hapludox) and a clayey Nitossolo Vermelho eutroférrico (Rhodic Kandiudalf) were monitored. The soil was sampled and data collected after 0, 3, 5 and 10 rain storms with intensities above 25 mm h-1, from December 2008 to May 2009. Soil chemical and particle size distribution analysis were performed. The changes caused by rainfall were monitored by determining the soil roughness, hydraulic conductivity and soil water retention curves and by micromorphological analysis. Reduced soil roughness and crust formation were observed for all soils during the monitored rainfall events. However, contrary to what was expected according to the literature, crust formation was not always accompanied by reductions in total porosity, hydraulic conductivity and soil water retention.
Keywords : surface crusting; soil roughness; micromorphology.