Superficial liming is an alternative way to correct soil acidity in no till system. The objective of this study was to evaluate the effects of superficial and incorporated liming on native pasture. The experiment was carried out at the experimental field of the Soil Science Department, at the Universidade Federal de Santa Maria (Brazil), on a Plinthaquult medium texture and with high potential acidity under native pasture. Lime rates of 0.0, 2.0, 8.5 and 17.0 Mg ha-1 were used. On half of the plots lime was mixed with the topsoil by disk plow and left on the surface on the other half of the plot. The experimental design was arranged in completely randomized blocks with four replications. After 6, 18, 36, and 48 months, soil was sampled at four depths, 0.0-2.5, 2.5-5.0, 5.0-10.0 and 10.0-15.0 cm and the attributes related to soil acidity evaluated. The surface applied lime was effective in neutralizing soil acidity, at a depth proportional to the rate and time. With 2.0 + 2.0 t ha-1, aluminum saturation reached near zero (0.0-2.5 cm layer) at 36 months; with 8.5 t ha-1, it reached near zero (2.5-5.0 cm) at 36 months; with 17.0 t ha-1 it reached near zero (5.0-10.0 cm) at 48 months.
acidity; movement of cations; bioporous; no-tillage system