Papers

Summary

The intensive use of the Oxisols in the northeast of São Paulo State with the sugarcane using extreme superficial preparation and burning of the residues significantly modifies the physical properties of the soil. This work had the objective to evaluate the spatial variability of physical attributes of an Oxisol under sugarcane crop, by applying the technique of geostatistics. The soils were collected at the grid points, with regular intervals of 10 m, at the depths of 0 - 0.2, 0.2 - 0.4 and 0.4 - 0.6 m, totaling 100 points. In each soil sample the total porosity, macroporosity, microporosity and bulk density of the soil were determined. The variation coefficient indicated low variability for the variables of total porosity in the layers 0.2 - 0.4 and 0.4 - 0.6 m, microporosity in the 0.2 - 0.4 m layer and bulk density in all layers and average variation for microporosity in the layers of 0 - 0.2 and 0.4 - 0.6 m and total porosity in the 0 - 0.2 m, while the macroporosity presented a high variation. The higher ranges were observed in the 0.2 - 0.4 and 0.4 - 0.6 m layers for all the studied attributes. The high values for the variable bulk density, mainly in the layer of 0.2 - 0.4 m, had promoted a reduction of the total porosity, mainly microporosity and in the macroporosity, indicating compaction of this layer. Small variations in the forms of the relief condition differentiated spatial variability for physical attributes.