The assessment of the soil erodibility (K-factor) is essential for using the universal soil loss equation. The objective of this paper was to verify the adequacy of different indirect methods to estimate the K-factors of soils with argillic horizon from diverse geographic regions of Brazil. Superficial samples of 22 soils bearing argillic horizon were collected. The K-factors measured directly in the field of all these soils are already known. Several chemical and physical analyses were performed in order to calculate the K-factor by 13 indirect methods. The calculated K-factors were correlated with the direct K-factor value. It was verified that none of the indirect methods tested is suitable for estimating the K-factor of all studied soils with argillic horizon in Brazil.
erosion; K-factor; USLE