Ciencia del Suelo (Dec 2011)
Propiedades hidrofísicas de un hapludol típico de Córdoba en relación al pisoteo animal Hydrophysical properties of a typical hapludol of Córdoba province, Argentina, in relation to animal trampling
Abstract
El objetivo del presente trabajo fue evaluar el efecto del pisoteo animal sobre algunas propiedades hidrofísicas de un Hapludol típico implantado con Triticale (Triticosecale Wittmack), mediante un sistema de pastoreo rotativo (7 días de ocupación y 42 días de descanso) con cuatro niveles de carga animal que correspondieron a asignaciones de forraje de 2, 4, 6 y 8 kg materia seca cada 100 kg (%) de peso vivo animal por día, en dos condiciones de humedad edáfica: Suelo Seco, con 11% y Suelo Húmedo con 18%. Se tomó como referencia un sistema no pastoreado. El ensayo se realizó en el campo experimental de la Universidad Nacional de Río Cuarto, al suroeste de Córdoba, bajo un diseño experimental en bloques al azar con arreglo en parcelas divididas. Se evaluó densidad aparente (DA), compactación relativa (CR), porosidad total (PT) a 0-5 cm y 5-10 cm de profundidad y velocidad de infiltración inicial (VII) y final (VIF). La DA presentó un aumento (pThe aim of this study was to evaluate the effect of animal trampling on some hydrophysical properties of a typical Hapludol implanted with «Triticosecale Wittmack», by means of a rotational grazing system (7 days of occupation and 42 days off) with four stocking rates corresponding to forage allowances of 2, 4, 6 and 8 kg dry matter/100 kg of live animal weight per day, under two soil moisture contents: dry soil, with 11% and moist soil, with 18% water content. The results were compared to an ungrazed reference system. The study was conducted at the experimental station of the Universidad Nacional de Rio Cuarto, southwestern Córdoba province, Argentina, under an experimental design in randomized blocks with a split plot arrangement. The parameters assessed were: bulk density (BD), relative compaction (RC), total porosity (TP) at 0-5 cm and 5-10 cm depths, and initial and final infiltration rate (IIR and FIR, respectively). BD showed an increase (p <0.05) at the 0-10 cm depth, which was more pronounced in the first 0-5 cm, and a decrease in the IIR and FIR as compared to the controls. The higher soil water content at the time of grazing increased these effects. RC values followed the same trend as those of BD, but did not reach critical values for crop development. The level of forage allowance and soil moisture at the time of grazing proved to be factors that modified the hydrophysical behavior of the soil under study. The increase in stocking rate caused a decrease in the IIR and an increase in BD, an effect that was enhanced under the wet soil condition. The forage allowances of 6 and 8% seemed to be stocking rates that do not modify the hydrophysical conditions of the soil in relation to the ungrazed condition.
