Dynamic of soil salinity in the Araras North Irrigated District, Ceará, Brazil
Keywords:
Soil-salinity, Plantas- effect of salt, Soils-leaching.Abstract
This work was carried out to develop a comparative study of Na+, Cl-, Ca2+ + Mg2+ e K+ concentrations between an irrigated area and undisturbed land, as well as to evaluate rainfall effects over lixiviation. The study was conducted in the Araras Norte Irrigated District (DIPAN), Ceará, Brazil. The studied was carried out in a grape (Vitis vinifera L.) orchard since 2001 and water was supplied by a microasprinkler system. The water used in the irrigation was classified as C1S2. Soils were sampled in the 0.00-0.30; 0.30-0.60 and 0.60-0.90 m layers, every two months from May/2003 to September/2005. According to the results, Ca2+ + Mg2+ concentration in irrigated area presented the highest increment in relation to undisturbed land, while sodium and potassium registered the lowest concentrations. The Cl- presented the highest concentration in the upper layer, while in deeper layers, its concentration was constant. Also, it was observed that the depth of total rainfall equal to 2,882 mm and was not enough to lead the saline status of the irrigated soils to the conditions registered in undisturbed land. The increasing in these ions concentrations can guide, in the future, to the degradation of irrigated soils in the Distrito de Irrigação do Perímetro Araras Norte.
