Ciencia e investigación agraria
versão On-line ISSN 0718-1620
MON, Rodolfo et al. Effects of supplementary irrigation on chemical and physical soil properties in the rolling pampa region of Argentina. Cienc. Inv. Agr. [online]. 2007, vol.34, n.3, pp. 187-194. ISSN 0718-1620. doi: 10.4067/S0718-16202007000300002.
The effects of supplementary irrigation on soil chemical and physical properties were studied in 21 locations in the north of the rolling pampa region of Argentina. The chemical and physical variables were measured in top soil (0-100 mm) to compare irrigated and non-irrigated soils. Chemical variables were: electrical conductivity (EC), pH, exchangeable sodium percentage (ESP), and organic mater content. Physical variables included structural index (SI) and percolation index (PI) measured in the laboratory, as well as infiltration, runoff, and soil losses, measured in the field with a small portable rainfall simulator. Water quality was established according to its chemical composition and Riverside USA classification. In irrigated soils, chemical data shows, on average, a slight increase in ESP (from 2.56 to 5.52) and in pH (from 6.13 to 6.45). EC, SI, and PI show the same values in irrigated and non-irrigated soils. The application of a simulated rainfall of 30 mm in 30 min revealed a different soil behavior. Irrigated soils present lower values of water entry and infiltration rates, and higher values of runoff and soil losses. The variation in chemical and physical soil properties show that within 10 years of supplementary irrigation a slight process of sodication and alkalinization occurs. Water quality and soil chemical data suggest that the sodication process and the increased soil erosion risk must be controlled in order to achieve a sustainable high production system
Palavras-chave : Erosion risk; infiltration; sodication; supplementary irrigation.