This research was carried out aiming at studying soil density variability, in a soil alluvial Embrapa Algodão Experimental Station, Sousa, Paraíba, Brazil. The area has a cropped surface of 17 ha and field trials were done on 40 sampling points, placed on the central longitudinal line of each agricultural plot, distant 50 m. On the soil density determination the volumetric ring was used, in deformed structural samples for three depths: 0-30, 30-60, and 60-90 cm. Spatial variability was determined by classical statistics and geostatistics. In the classic statistical analysis of the soil density for the three depths presented standard deviation and variation coefficient low values, indicating low variation of the soil density with the increase of the depth. The of soil density manifested structure of spatial dependence, modeled through semivariograms, it was interpolated for "Kriging", the presenting spherical structure on 0-30 and 60-90 cm depth, reaching 46 m for both depths exponential structure reaching 255,10 m for 30-60 cm of depth.
geostatistics; semivariograms; spatial dependence; kriging
