Ciencia del Suelo (Dec 2012)
Relación de la inestabilidad estructural con el manejo y propiedades de los suelos de la región pampeana Relation of structural instability with management and properties of soils in the Pampean region
Abstract
La inestabilidad estructural (IEST) permite caracterizar la resistencia a la degradación de los suelos. Se determinó la IEST (De Leenheer& De Boodt) en 67 sitios de muestreo bajo distintos manejos en la Región Pampeana norte, con el objetivo de comparar los manejos y analizar su relación con: a) la densidad aparente (DAP); b) el contenido de carbono orgánico total y sus fracciones particulada (> 53 mm) y resistente (Soil structural instability (IEST) characterizes the resistance to degradation of soils. Soil IEST (De Leenheer and De Boodt) was determined in 67 sites under different soil managements in the Northern Pampean Region, in order to establish its relation with: a) core bulk density (DAP); b) total organic carbon and its particulate (> 53 mm) and resistant (<53 mm) fractions; c) granulometric fractions; and d) relative compaction (ratio bulk density to maximum bulk density by Proctor Test). Soil IEST allowed distinguishing among quasi-pristine and agriculture under tillage (P<0.05). Meanwhile integrated crop-livestock systems under no tillage and agriculture under no tillage presented intermediate values. DAP was highest in the integrated crop-livestock systems under no tillage. A multiple regression model (R2 = 0.37) was fitted between IEST and total organic carbon and silt content and a Dummy variable related to management. DAP was negatively related with total organic carbon and clay content and positive with a Dummy variable (value= 1 for integrated crop-livestock systems and 0 for the others) (R2= 0.62). Results suggest other stabilizing agents like the action of plant roots could be responsible for the variation in SI in these soils. It can be concluded that higher carbon contents are required to stabilize silty soils.
