Validity of the centrifuge method for determining the water retention properties of tropical soils
This study compared the centrifuge and pressure plate methods with appropriate run durations. Samples collected in tropical soils located in Brazil along a 10-km local hydrosequence across the Cerrado–Amazonia transition (Set 1) and along a 350-km regional toposequence across the Cerrado region (Set 2) were selected to compare and discuss statistically the similarity of the soil water retention recorded by using the pressure plate and centrifuge methods. The results showed good agreement (R2 = 0.99) for the 1:1 comparison of measured pointwise soil water content values (Set 1) as well as for the fitted soil water content curves by the van Genuchten model using data points obtained with the two methods (Set 2). Thus, the centrifuge method should be considered as an appropriate method for determining soil water retention properties not only because of similar results with the pressure plate method but also because it is much less time consuming.