Micromorfologia e tomografia de raios-X: porosidade de um latossolo gibbsítico sob sistema multi-práticas de manejo cafeeiro

Abstract

Our aimwas to evaluate the pore morphologyof an Oxisol subjectedtocoffeemulti-practice management system with different doses of gypsum byanalysis of 2 and 3 D.The design was in randomized blocks with three treatments: G0-absence of gypsum; G7 and G28, with 7 and 28 Mg ha–1of additional gypsum, respectively, applied to the soil surface in the planting row, in three layers: 0.20-0.34 m; 0.80-0.94m and 1.50-1.64m.Undesturbed soil samples were collected in acrylic tubesin the planting row, in three replications. Imageanalyzes obtained via X-ray computed tomography and micromorphology in thin sections were used. Data were subjected to descriptive statistical analysis.The typical Oxisolmicrostructure remained granular, consistent with the predominance of gibbsite in the clay raction. Inthe micromorphology, there was a large amount of packing-type pores (70%) and cavities (10%) and a change in the weft, from porphyric to enaulic, according to the increase in gypsum. In the X-ray tomographic images, greater morphological diversificationof the pores was detected, especially in G28, with a predominance of platypores (Triaxial, 12%), channels or biopore(Prolate,12%) and packing/stackingvoids(64%), as well as accounting for thema greater number (n>30,000) and categories of pores were obtained due to the greater detail of the technique, such as biopores (G28>G7=G0) and platypores (G28>G7=G0).The techniques complement eachother, the micromorphology allowed to evaluate the structuralorganization with quality and the X-ray tomography quantified more pores due to the higher spatial resolution and the algorithms.