Modeling the Requirements of Agricultural Limestone in Acid Sulfate Soils of Brazil and Colombia

The aim of this study was to model the determination of the amount of agricultural limestone necessary to correct acidification in acid sulfate soils (ASS). This study used 14 equations and the chemical variables of the soils including pH, soil organic matter (SOM), potential acidity (H+ Al), sum of bases (BS), potential acidity (T), base saturation (V) and exchangeable Al with KCl. The results indicated that in the studied, the lowest requirements for doses of limestone (DL) were described by the equations DL = 2.906((H+ Al) (45-V)/100)degrees(80), DL = 0.08 + 1.22Al(KCl), DL = 0.6T - BS, and DL = 1.5Al(KCl), with mean values of 29.5, 30.5, 31.5 and 37.4 t ha(-1). In addition, the models with the best correlation for determining the limestone requirements to obtain 80% of the maximum production of sorghum (dry matter) were DL = -1.43 + 0.9237 (SOM (6-pH)) and DL = -0.022 + 2.7425 ((H+ Al) (45-V)/100).