Resilience of soils with different texture, mineralogy and organic matter under long-term conservation systems

Abstract

The ability of soil to recover from disturbances is important for the proper functioning of agroecosystems. The objective of this study was to investigate the effect of the physical resilience in subtropical soils, due to organic matter content, texture, and mineralogy. For this purpose, both undisturbed soil core and disturbed soil samples were taken from two depths from three soils under no-tillage in long-term field experiments: two Oxisols and one Ultisol. Soil core samples were subjected to wetting–drying cycles and the soil physical attributes (bulk density, total porosity, macro- and microporosity, and air permeability) were determined before and after soil compaction or wet-dry cycles. Organic matter and clay contents were greater in the Oxisols, with iron oxides, reducing the stress level. Soil bulk density, total porosity, macro- and microporosity, and air permeability returned values like their originals after compaction and three wetting–drying cycles. Macroporosity was the individual attribute most strongly affected by compaction and it recovered to the greatest extent. The Oxisols were more resilient than the Ultisol due to their higher organic matter, clay contents and the presence of iron oxides.