Rev. Bras. Ciênc. Solo.2000;24(3):689-792.

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Estimation of potential acidity by pH SMP in soils from Northeastern Brazil

C. A. Silva, M. L. Avellar, A. C. C. Bernardi

01/Sep/2000

DOI: 10.1590/S0100-06832000000300023

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 SMP)² -451.61 pH SMP + 1625.3 (R² = 0.87**), with H + Al in mmol_c dm^-3, provides a good estimation of potential acidity by using the pH SMP.