Spatial variability and estimate of critical sites for bulk density in an oxisol

Abstract

The soil physical condition is complexand must be analyzed in terms of a set ofspecific indicators and their inter-relations. Thiswork aimed to evaluate the spatial variability ofbulk density and related effects from otherphysical attributes in an experimental area ofOxisol in order to detect and estimate sites withcritical values for root development. Linearmodels were fitted to the spatial bulk density inlayers 0-0.2 and 0.2-0.4 m, considering theGaussian process. Models were adjusted withand without a principal component, and modelscontaining the covariate density in the previouslayer to depth of 0.2-0.4 m. Performed kriging,probability maps to obtain bulk density above1.4 kg dm-3 were constructed based on 1000simulations from predictive distribution. Therewere sites with critical values of soil density.There were no related effects of moisture, sand,silt and clay in the bulk density levels, however,it was no influence from upper layer in the layerdensity levels on 0.2-0.4 m. There was evidenceof sites over 80% probability of occurrence ofcritical levels of bulk density, in the two layers.