Three-dimensional interpolation of soil data: fertility and pedomorphological features in southern Brazil

• Published in: Revista Brasileira de Ciência do Solo 2014-08, Vol.38 (4), p.1091-1100
• Main Authors: Piedade, Tales de Campos, Melo, Vander de Freitas, Souza, Luiz Cláudio de Paula, Dieckow, Jeferson
• Format: Article
• Language: English
• Subjects: acidez do solo; geoprocessamento; GRASS GIS; ParaView; SOIL SCIENCE; volume de solo confinado
• ISSN: 0100-0683; 1806-9657; 0100-0683
• DOI: 10.1590/S0100-06832014000400005

The graphical representation of spatial soil properties in a digital environment is complex because it requires a conversion of data collected in a discrete form onto a continuous surface. The objective of this study was to apply three-dimension techniques of interpolation and visualization on soil texture and fertility properties and establish relationships with pedogenetic factors and processes in a slope area. The GRASS Geographic Information System was used to generate three-dimensional models and ParaView software to visualize soil volumes. Samples of the A, AB, BA, and B horizons were collected in a regular 122-point grid in an area of 13 ha, in Pinhais, PR, in southern Brazil. Geoprocessing and graphic computing techniques were effective in identifying and delimiting soil volumes of distinct ranges of fertility properties confined within the soil matrix. Both three-dimensional interpolation and the visualization tool facilitated interpretation in a continuous space (volumes) of the cause-effect relationships between soil texture and fertility properties and pedological factors and processes, such as higher clay contents following the drainage lines of the area. The flattest part with more weathered soils (Oxisols) had the highest pH values and lower Al3+ concentrations. These techniques of data interpolation and visualization have great potential for use in diverse areas of soil science, such as identification of soil volumes occurring side-by-side but that exhibit different physical, chemical, and mineralogical conditions for plant root growth, and monitoring of plumes of organic and inorganic pollutants in soils and sediments, among other applications. The methodological details for interpolation and a three-dimensional view of soil data are presented here. A representação gráfica dos atributos espaciais do solo em um ambiente digital é uma tarefa complexa, pois requer a conversão de dados coletados de forma discreta para uma superfície contínua. Os objetivos deste estudo foram aplicar técnicas tridimensionais de interpolação e visualização da textura e dos atributos de fertilidade do solo e estabelecer relações com fatores e processos pedogenéticos em uma área de encosta. Os programas GRASS e ParaView foram utilizados para gerar modelos tridimensionais e visualizar volumes de solo, respectivamente. Amostras dos horizontes A, AB, BA e B foram coletadas em uma grade regular de 122 pontos em uma área de 13 ha, em Pinhais, PR, sul do Brasil. As técni