Potential acidity is of great importance for the base saturation determination and for the recommendation of liming. The objective of this study was to evaluate the relationship between pH SMP and H + Al contents, in order to establish an equation for the potential acidity estimation of soils from Northern Minas Gerais, Brazil. The H + Al concentration (0.5 mol L-1 calcium acetate pH 7.0) and pH SMP were analysed at EPAMIG/CTNM soil fertility laboratory, in 50 soil samples. The […]

The determination of soil potential acidity (H + Al) extracted by the 0.5 mol L-1 calcium acetate solution is a routine analysis in Brazilian soil laboratories. However, due to analytical facilities, it is becoming a regular procedure to estimate the values of potential acidity using the equilibrium pH of the soil suspension with the SMP solution. The aim of this study was to look at the relationship between pH SMP and H + Al in soils of Pernambuco, in order […]

In this study the relationship between the pH SMP and H + Al concentrations was evaluated, in order to establish an equation for estimating the potential acidity of soils from Northeastern Brazil. The H + Al concentration (calcium acetate 0.5 mol L-1, pH 7.0) and pH SMP were analyzed in 81 soil samples. Soil carbon content ranged from 1.8 to 35.6 g kg-1, and clay content varied from 60 to 590 g kg-1. The equation H + Al = 31.521(pH […]

The experiment was conducted under greenhouse conditions at the Soil Science Department of the Federal University of Lavras, Lavras, from August 1995 to June 1996. The objectives were to evaluate the application of limestone on several chemical properties and on the nutrition and production of common bean cultivated in samples of four lowland soils and to compare the doses established as appropriate according to base saturation and Al and Ca + Mg methods. A 6×4 factorial scheme in a completely […]

The potential extractable acidity method by Ca(OAc)2 0.5 mol L-1 is widely used in Brazilian soil analysis laboratories. To define the calibration curve between potential extractable acidity and buffered pH SMP, 102 samples of soils from Rio de Janeiro State, Brazil, were analyzed in 1996. The data showed that potential acidity can be estimated by pH SMP buffer suspension (R2 = 0.90**) and that the pH of Ca(OAc)2 0.5 mol L-1 suspension was significantly correlated with the pH SMP.