Validity of the centrifuge method for determining the water retention properties of tropical soils

Abstract : This study aims at comparing the centrifuge and pressure plate methods when appropriate duration of run is adopted. 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 point-wise soil-water content values (set 1) as well as for the fitted soil-water content curves by 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 for the similar results with the pressure plate method but also for being much less time consuming.