Variabilidade espacial de atributos físicos e químicos de um Latossolo argiloso correlacionados ao rendimento de grãos da cultura do Crambe (Crambe abyssinica Hochst)

Abstract

The objective of this study was to verify, with the help of thematic maps obtained by kriging, the existence of correlationship of physical and chemical attributes with the yield of crambe (Crambe abyssinica Hochst) in clayey Oxisol under no-tillage system. To this end, we conducted research in an experimental area in the city of Cascavel - Paraná - Brazil. The experimental grid was established in an area with dimensions of 100 x 100m, marked every 10m in two directions perpendicular to one another, totaling 100 points, samples were collected for bulk density and soil resistance to penetration depths of 0-0,1, 0,1-0,2 and 0,2-0,3m, partially deformed samples to determine soil pH, MO, P and K as well as samples for determining the yield of the crambe. Statistical analyzes were performed using the software R, and the geostatistical analysis was performed using the package GeoR. In developing the experimental semivariograms were used estimators Matheron and Cressie & Hawkins and adjustments of the theoretical semivariogram methods were used ordinary least squares and weighted least squares. Theoretical models have been adjusted and the spherical exponential, and the choice of the best model has been performed by means of cross-validation. The results showed a weak correlation between the thematic maps of physical and chemical properties of soil with the crop yield of crambe. The maps RSP1 and pH showed the highest correlation with yield. Chemical characteristics showed higher correlation with higher levels of productivity at pH ≥ 5,0, MO ≥ 5,5 m/v (%), P ≥ 15,0 mg dm-3 and K ≥ 0,4 cmolc dm-3.