Changes on aggregates morphology and roughness induced by different uses of Typical Argiudolls, Buenos Aires province, Argentina

Over the last few years, the increase of agriculture in the Pampean plains has led to a significant degradation of the most fertile soils in the country. The aim of our work is to define the effect of soil use on the stability of aggregates, bulk density and penetration resistance, and, especially, on the morphology and roughness of aggregates for their evaluation as possible soil quality indicators of Typical Argiudolls of south-eastern Buenos Aires. Mollic epipedons of plots with different soil use were analyzed: cultivated, pasture, and natural plots.The results indicated that bulk density values (>1.2 g/cm3) and penetration resistance (2–4.4 MPa) values were significantly higher (p < 0.05) in the cultivated sites when compared to natural soil (1 g/cm3 and 1.5–3 MPa respectively). Aggregate stability was significantly lower (p < 0.05) in the cultivated plots with respect to the natural plot, showing stable aggregates with values of 60–80% (crop intensive) and 85–100% (crop extensive). Moreover, these areas showed a greater percentage of spherical aggregates, and less rough than those in the natural plots. All of the properties were affected by soil use. The morphology and roughness of aggregates are effective indicators to help in the evaluation the quality of Typical Argiudolls of south-eastern Buenos Aires.

► We examine evaluated the effect of soil use on the stability, morphology and roughness of aggregates, bulk density and penetration resistance. ► Mollic epipedons of Typical Argiudolls of Buenos Aires with different soil use were analyzed: cultivated, pasture, and natural plots. ► Bulk density, penetration resistance, and aggregate stability are properties that are being used as indicators of soil quality. ► The morphology and roughness could also be included in the set of physical indicators of soil quality of these Typical Argiudolls.