Soil hydraulic conductivities of latosols under pasture, forest and teak in Rondonia, Brazil

We investigated the changes of saturated hydraulic conductivity, K-sat, wit h depth of latosols developed on Precambrian basement rucks under primary r ainforest, pasture and teak. In all cases, K-sat decreased with depth, with most of the decrease occurring between the surface and a depth of 30 cm. I n conjunction with prevailing rainfall intensities and frequencies. this an isotropy supports a pronounced lateral component of hillslope flow paths. a nd also of overland flow under pasture. Our results are at variance with da ta from other latosols where K-sat tends to increase with depth, and hence suggest that considerable restraint is needed in generalization and extrapo lation until results from a co-ordinated effort at hydrology-oriented data collection become available. Copyright (C) 1999 John Wiley & Sons, Ltd.