Soils in the region of Campos de Cima da Serra, RS, have high organic matter contents (SOM) and high levels of exchangeable Al. This study aimed to investigate the SOM quality of surface samples (0-10 cm) of eight representative soils from the region (two Neossols, two Gleissols, three Cambissols, one Latosol) under native pasture. The objectives were to evaluate the sample behaviour under demineralization with HF solution, to determine the chemical composition and the influence of exchangeable Al and iron […]

Soil organic matter from the surface horizon of two Brazilian soils (a Latosol and a Chernosol), in bulk samples (in situ SOM) and in HF-treated samples (SOM), was characterized by elemental analyses, diffuse reflectance (DRIFT) and transmission Fourier transform infrared spectroscopy (T-FTIR). Humic acids (HA), fulvic acids (FA) and humin (HU) isolated from the SOM were characterized additionally by ultraviolet-visible spectroscopy (UV-VIS). After sample oxidation and alkaline treatment, the DRIFT technique proved to be more informative for the detection of […]