Water-vegetation interaction in the arid: influence of Bulnesia retama (Zygophyllaceae) on the infiltration rate, in the southern zone of the Bermejo Basin, San Juan (Argentina).

TAPIA, RAÚL.; MARIANA MARTINELLI

BIOCELL

Instituto de histología embriología CONICET

Año: 2018

The influence of Bulnesia retama was studied on the infiltration rate in a pilot site of thebasin Bermejo (San Juan). Infiltration is related to surface runoff, recharge of aquifersand it vulnerability to contamination; is affected by soil texture and structure, organicmatter content, initial moisture and vegetation cover. The field data were taken byhomogeneous units defined on the basis of digital processing of an elevation model anda satellite image visual interpretation. Was performed morphometry on the basin,defining microbasins on a scale of 50,000 cells. Five linear transects of 50 meters weremade, measuring coverage with the technique of intersection per line. The infiltrationtests were performed inside and outside the canopy, with a simple ring infiltrometer (21cm diameter) and variable load. The data were adjusted according to the diameter of theinfiltrator. Soil samples were taken, determining: organic matter content, texture, totalnitrogen, conductivity and pH. The average coverage of B. retama was 34%, of the baresoil, 44%. The rate of infiltration was higher below the canopy of B. retama (slope6.5%) compared to bare soil (4%). The results suggest that the presence of B. retamafavors the velocity of infiltration in the soil.