Soil susceptibility to compaction under use conditions in southern Brazil

Abstract

The degree of soil compaction is intensified by its inadequate management, compaction being variable depending on soil type since even under identical management conditions, different types have different abilities to withstand load. The objective of this study was to evaluate the susceptibility to compaction of different classes of soils under no-tillage (NT) croping system compared to the original condition. Thus, i) soils with the same source material have distinct resistance to compression with increased NT adoption time; ii) the most sensitive indicators of this change are the ratios mass:volume and volume:volume and; iii) there is a relationship between resistance and compaction susceptibility with the amount and type of oxide. Soil samples were collected in areas under NT and under natural condition in order to assess the impact imposed by the NT on the attributes density and porosity, precompression stress and compressibility index and relate them to the oxide type of, and content in, the soils under study. The results show that the density and macroporosity were those most affected by the NT agricultural use, regardless of soil type, that is, its dynamic is related more to soil use and less to mineralogical characteristics. The soil resistance and compaction susceptibility were higher in soil developed in basalt, followed by those developed in sandstone and granite. Both the organic matter content and type and concentration of iron oxides were related to the soil resistance and susceptibility to compaction.

3D analysis of the soil porous architecture under long term contrasting management systems by X-ray computed tomography

“…The number of disconnected pores was c. 1.5 times higher for ZT than CT. The lowest porosity observed for ZT maybe associated with a "zero-tillage pan", which can happen in areas under long term ZT as previously observed in the South of Brazil down to 20 cm soil depth (Mazurana et al, 2017;da Silva et al, 2009;Klein and Libardi, 2002). According to Reichert et al (2007), soil compaction in ZT can occur mainly when this practice is utilized for long periods due to machinery traffic, low soil mobilization and natural soil arrangement.…”

Soil load support capacity increases with time without soil mobilization as a result of age-hardening phenomenon

“…Soil load support capacity is affected by several soil attributes, e.g., organic matter content, texture, type and concentration of iron oxides (Mazurana et al, 2017), water content (Tang et al, 2009), bulk density (Assouline, 2002), porosity (Veiga et al, 2007), structure (Veenhof and McBride, 1996), and especially the cohesion and adhesion forces among soil particles (Horn, 2004). However, soil load support capacity has rarely been related to soil strengthening resulting from the age-hardening process (Moraes et al, 2017).…”

Physical and chemical properties of an oxisol after maize cropping on rotation with leguminous plants

“…Although the increase in pore has been expected when using management with cover crops, biological pores represent less than 3% volume of soil and their formation reduces in a little way density, however, in air and water flows concerning profile, they have a major effect, often undetected by traditional methods (Reinert et al, 2008). It must be considered that the soil structure can be altered by agricultural use (MAZURANA, et al, 2017). Table 1.…”