Soil porosity in integrated and non-integrated grazing systems in a Brazilian Ferralsol assessed by 3D X-ray computed tomography

Author(s):Show less -

Valani, Gustavo Pereira ; Martini, Aline Fachin ; Machado, Cassia Bezerra ; Duarte, Daniel Amancio ; de Brito, Marcio Fernando Paixao ; Pezzopane, Jose Ricardo Macedo ; Bernardi, Alberto Carlos de Campos ; Antonino, Antonio Celso Dantas ; Heck, Richard John ; Gimenez, Daniel ; Cooper, Miguel

• Document type: Journal article
• Source: COMPUTERS AND ELECTRONICS IN AGRICULTURE; v. 237, p. 13-pg., 2025-10-01.

Abstract

Integrated grazing systems enhance soil quality; however, little is known about the impact of these systems on the properties and spatial density of soil pores. This study evaluates three-dimensional pore characteristics in a Brazilian Ferralsol under integrated and non-integrated grazing systems. Six soil management systems were studied: continuous grazing (CONT), rotational grazing (ROT), integrated crop-livestock system (ICL), integrated livestock-forest system (ILF), integrated crop-livestock-forest system (ICLF), and native vegetation (NV). Samples from four depths, 0 - 12 cm, 12 - 24 cm, 26 - 38 cm and 84 - 96 cm, were scanned with an X-ray computed tomography instrument at a spatial resolution of 50 mu m. The scanned volumes were reconstructed and segmented. Image analyses included the percentage, size, shape, orientation and connectivity of image-based pores, the fractal dimensions D0, D1, D2, and the parameters Delta alpha, alpha ratio and f(alpha)ratio from multifractal analysis, as well as entropy assessments. Differences between soil management systems and soil depths were compared by one-way ANOVA on ranks. Soil compaction reduced image-based porosity down to 38 cm in all grazing systems in relation to NV. Compaction also altered pore morphology, decreasing triaxial, prolate, oblate, and equant pores while increasing complex-shaped pores. The two most common pore orientation classes were nearhorizontal and inclined, which accounted for over 70 % of the distribution in each system. The only system with negative Euler numbers for all soil layers studied was NV, which implies that grazing reduces pore connectivity when compared to natural vegetation. Pore systems tended to have more clearly defined multifractal properties near the surface than deeper into the soil. Most noticeable differences in pore entropy were found between 26 and 38 cm, being highest in NV, intermediate in integrated grazing systems with trees (ILF and ICLF) and lowest in other grazing systems (CONT, ROT and ICL). The outlook of this work is that soil management strategies for integrated systems must avoid soil compaction by adjusting stocking rates, controlling traffic, maintaining soil cover and diversifying crop rotation. (AU)

• FAPESP's process: 19/14144-0 - Soil physical quality in integrated agricultural systems, pastures and native forest: correlation between on-farm, analytical and digital measurements
• Grantee: Gustavo Pereira Valani
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 23/02444-5 - Understanding intensified and integrated production systems: from the quantum world to low-carbon agriculture
• Grantee: Ladislau Martin Neto
• Support Opportunities: Research Program on Global Climate Change - Thematic Grants