Carla Eloize Carducci

Scaling of pores in 3D images of Latosols (Oxisols) with contrasting mineralogy under a conservation management system

The aim of this study was to evaluate the spatial and morphological configuration of the pore space in 3D images of Latosols with different mineralogy under a conservation tillage system in a coffee crop area. The visualisation and quantification of pore size distribution by data mining and spatial variability by semi-variogams were investigated in 3D images with 60-µm spatial resolution generated by X-ray CT scan (EVS/GE MS8x-130) in soil core samples collected at different depths of a kaolinitic Red-Yellow Latosol (RYL) and a gibbsitic Red Latosol (RL) from Brazil. Greater spatial variability occurred in the horizontal direction of the 3D image, a novel finding in this area of research. The pores detected were different between the Latosols studied, mainly at 0.20–0.34 m depth. The largest number (>4000) and volume (±30 mm3) of pores was found in the RL. The soil classes differed in 3D pore characteristics, and this aspect may be important in the characterisation of causes of pore variability. Sphericity was similar for both soils, with greater emphasis on pore classes with a diameter 15%).

Distribuição espacial das raízes de cafeeiro e dos poros de dois Latossolos sob manejo conservacionista

The aim of this study was to evaluate the effect of management system employing soil conservation practices in the coffee root system distribution and in the structure of two Latosols after six years in the crop establishment in Alto Sao Francisco Valley, MG. Three random trenches were made lengthwise along the row planting (0.70 x 1.50 m) in a gibbsitic Latosol and a kaolinitc Latosol both under soil management system employing soil conservationist practices. The root system evaluation was done by crop profile methods and 2D image analyze, with subsequent surface mapping of the root variables analyzed by kriging. Intact soil cores were sampled for pore diameter distribution analysed by X-ray CT scan. The roots and pores were classified by diameter:1, > 1 and ≤ 3 and > 3 mm. The coffee root system in both soils under study on the same management system showed good branching in horizontal and vertical direction. The highest root concentration occurred at 0.20-0.34 m depth in kaolinitic Latosol. In gibbsitic Latosol the root distribution was uniform, especially in the vertical soil profile reaching greater depths. The highest occurrence of fine roots in the gibbsitic Latosol occurred at 0.80-0.94 m depth.