Due to its analytical practicality, the SMP buffer solution method has been widely used in Brazilian soil laboratories in estimation of soil potential acidity (H+Al) instead of the extracted by 0.5 mol L-1 calcium acetate solution. However, regionalized studies are indispensable for reliably estimating values of potential acidity. The aim of this study was to fit a regression equation with good predictive capacity of the H+Al values based on measurement of the pH(SMP) for soils of the State of Paraiba, […]

The alluvial soil of the Assunção Island, in the São Francisco River, Cabrobó, State of Pernambuco, Brazil, has been intensively cultivated with annual crops under irrigation. The present yields are unsatisfactory due to the use of inadequate agricultural practices that are not sustainable. This study aimed to survey the soil chemical properties in an area of 1,131 ha by collecting 1,053 samples in the 0-0.30 m surface soil layer. The samples were analyzed for chemical properties and the data were […]

The present study investigated the reactivity of a slag from steelworks in different particle size fractions, applied on an acid dystrophic Red Latosol, under laboratory conditions, in a 4 x 3 + 2 factorial scheme in four replications. Four particle sizes (material retained in the ABNT 5-10; 10-20; 20-50, and < 50 sieves), three doses of slag (0.00, 5.04, and 10.08 t ha-1, corresponding to 0.00, 1.01, and 2.02 g in 0.40 dm3 of soil per cup) and two control […]

The determination of the potential acidity (H + Al) of soil samples by the calcium acetate 0.5 mol L-1 pH 7.0 method (conventional method) is most used in Brazilian laboratories. Other methods, which are more practical for routine analyses, have been tested with success for various soil groups, but not for those located in the northeast of the State of Pará. With this objective, twenty-seven representative soil samples were analyzed by the conventional Ca(OAc)2 method. The pH of equilibrium in […]