The objective of this work was to studying the spatial variability of some chemical properties of a saline-sodic soil of alluvial origin, in the Irrigated Perimeter of São Gonçalo, district of Sousa-PB, Brazil. At an experimental area of 2912 m², soil samples were collected in a grid with a spacing of 4 x 4 m, at a layer depth of 0 to 0.30 m. The data analysis was carried out by means of descriptive statistics and geostatistics. The results showed that the cation exchange capacity (CEC) presented normal distribution, and the data of electrical conductivity (EC), potassium and magnesium suggested lognormal distribution; the remaining chemical properties did not follow the probability of distributions evaluated. The highest coefficients of variation were found for magnesium, calcium and electrical conductivity (EC), and the lowest for the pH. Spatial dependence analysis showed that exchangeable sodium percentage (ESP), K and Ca presented a strong spatial dependence and CEC, EC, Mg , Na and the pH a moderate spatial dependence, ranging from 12 m (EC and CEC) to 27 m (Ca).
descriptive statistics; semivariogram; spatial dependence; soil chemistry