ABSTRACT Lime applications are used in acid soils to correct pH and eliminate Al3+ toxicity in crops. The lime rates are determined based on the estimated soil potential acidity (H+Al), using soil incubations with calcium carbonate (CaCO3) for 180 days, being a time-consuming and laborious process. An alternative method with calcium hydroxide [Ca(OH)2] for 96 h incubation may efficiently estimate H+Al, but it needs further studies. Also, soils from specific regions in southern Brazil have high organic matter (SOM) contents […]

The potential acidity is important because it is used in the determination of base saturation and the estimation of lime requirement. The objective of this study was to establish a regression equation to estimate the potential acidity with the SMP-pH measured in water under agitation of the SMP equilibrium solution with soil samples from the Jequitinhonha Valley, Minas Gerais State, Brazil. The H + Al concentration measured by 0.5 mol L-1 calcium acetate pH 7.0 and SMP pH  were determined in 50 soil samples at […]

The efficiency of surface application of lime under a no-tillage system is doubtful, particularly with regard to subsoil acidity and to methods of lime requirement determination. A field experiment was carried out on a dystrophic Dark Red Latosol (Haplortox) from Ponta Grossa, Paraná, Brazil, from 1993 to 1998, to evaluate the extent of downward movement of lime applied on the surface under a no-tillage system, and the effect on crop rotation grain yields. A randomized complete block design was used, […]