Surface liming of soil under no-tillage forms a concentration gradient of lime or its reaction products in the soil profile. The objective of this study was to evaluate the effects of surface liming on chemical attributes related to soil acidity. The experiment was carried out at the Federal University of Santa Maria, Southern Brazil, on a Typic Hapludult. The experiment was installed in October 1994 on a soil under no tillage since 1988. The treatments were: without lime; superficial reapplication of lime to elevate the pH to 6.0, totally added in the beginning of the experiment; half of the lime requirement in the beginning and the other half at the third year and a third of lime requirement, each year, during the first three years. The experimental design was completely randomized blocks with four replications. In October 2001, 84 months after liming, three trenches per plot were open and the soil sampled in layers of 1cm to 10cm of depth, of 2,5cm to 25cm, of 5cm to 50cm and the layer of 50-60cm. Surface applied lime was effective in neutralizing soil acidity in the soil profile and caused migration of calcium and magnesium in all the A horizon.
lime; soil acidity; alluminum saturation; movement of cations; biopores
