Determinação da variabilidade espacial de alumínio em função da distribuição de argila em solos de Querência do Norte/Paraná, Brasil

Abstract

The major part of Brazilian soils shows elevated aluminum contents and in several cases this element occurs in phytotoxic levels. Aluminum is a constituent of the soil's clay minerals. Its release can occur to the exchangeable fraction or to the soil solution. The objective of this work was to demonstrate the relationship between the spatial variability of aluminum and the distribution of soil clay. In order to achieve that, a grid of soil samples was collected in field, defined by means of photointerpretation and observation of images. The results obtained in laboratory were submitted to statistical analyses to verify spatial dependence, which was proven later. The space continuity was studied by means of the semivariogram's elaboration using different models. The best semivariograms were chosen by cross validation performed through "ordinary kriging". Thus, it could be observed that these variables showed structure of spatial dependence, with a positive correlation between them, besides it was possible to make maps in order to allow a better agricultural exploitation.