ABSTRACT
In arid and semi-arid regions of the world, high evaporative demands and pedogenetic characteristics of soils, associated with deficiencies in the drainage system in irrigation districts, contribute to a high potential of soil salinization process. Therefore, this study aimed to determine the degree of salinization in the irrigated area and evaluate the process of salt accumulation in the dry season and the potential for leaching of these salts by rainwater in the California Irrigation District, in the State of Sergipe, Brazil. Measurements of electrical conductivity of the saturated soil-paste extract (ECe), in dS m-1 at 25 °C, were performed at the beginning and the end of rainy seasons of the years 2008 and 2009. The sampling density was uniformly distributed throughout the District area. Geostatistical analysis was applied to ECe data and maps of spatial distribution of salinity were generated using ArcGIS® software. The ECe values obtained show that the salt accumulation process was not significant for both surface and subsurface soil layers (0-0.20 and 0.20-0.40 m), despite the intensive irrigated agriculture practiced for a long time. The average values of superficial ECe ranged from 0.47 up to 1.1 dS m-1, which are below the salinity threshold for most annual and perennial crops.
Key words:
irrigation; soil salinization; seasonal variation; spatial analysis