In soils of tropical climate regions the high acidity and the presence of exchangeable aluminum (Al3+), associated to low fertility, are the main restrainting factors for agricultural production. A laboratory experiment was conducted using 26 soils of different Brazilian regions, to investigate soil acidity components, giving emphasis to Al and their relations with chemical properties. The pH correlated positively with P, Ca, Mg, K, BS, CEC and V% values, and negatively with Al saturation. The Al3+ was the predominant exchangeable cation in 32% of the soils with pH below 5.6. The KCl titratable H+ represents the hydroxi-Al(OH)x complex with low stability and the Wolf-Morgan extracted Al corresponds to the exchangeable + non-exchangeable Al species. The... |