Variabilidade espacial da resistência do solo à penetração em um latossolo vermelho distroférrico

Abstract

The objective of this study was to evaluate the spatial variability of the penetration resistance of an Oxisol. The field experiment was installed in the Experimental Farm of the Federal University of Grande Dourados, Dourados, Mato Grosso do Sul, Brazil. An experimental area of 5.02 ha and sampling grid of 25 × 25 m, with points georeferenced using a GPS, was used. The penetration resistance was determined using a 60 cm penetrometer rod. The soil humidity in the area at the time of data collection was 18.5 % dry base. Data were analyzed using the geostatistics software GS+ and the maps were made in the software Surfer, version 8. The layer ranging between 12 and 16 cm showed higher mean resistance values than the other studied layers. The spatial dependence degree was classified as moderate for all layers. The models that best fitted the spatial distribution of the penetration resistance values were the exponential (depths of 12 and 16 cm) and linear models (8 and 20 cm). The sampled data can be used to build a GIS database for future analysis and decision making regarding the procedures for soil management.