This work aimed to diagnose current agricultural soil use as well as its implications for the spatial variability of soil bulk density (Ds), organic matter (OM), particle-size distribution and water dispersible clay (WDC), in Ribeirão Marcela watershed, belonging to Alto Rio Grande region, using geostatistics tools, in order to observe occurrence patterns of these attributes in the landscape. Disturbed and undisturbed soil samples were collected in 0-0.15 m layer, in a grid of 240 x 240 m (macro-scale) and 60 x 60 m (micro-scale), resulting in 165 samples. Current soil use is not in accordance to soil class agricultural suitability. Soil bulk density presented values between 1.05 and 1.15 g cm-3, this range being above characteristic values for Oxisol (close to 0.95 g cm-3), with the highest values found in lands under pasture. Organic matter values ranges from 1.5 to 4.5 dag kg-1, detecting higher concentrations in lands under eucalyptus, cerrado and wetlands. Particle-size distribution presented behavior following the drainage pathways and WDC presented low values in the entire watershed. Kriging maps were shown to be important tools for the understanding of spatial variability of physical soil attributes in the watershed, indicating critical management areas.
watershed; kriging; use and occupation of soil
