COMPOSIÇÃO DO LIXIVIADO EM QUATRO SOLOS DO RIO GRANDE DO NORTE IRRIGADOS COM ÁGUAS SALINAS

In many areas irrigated of the world, water supply of good quality not be enough for the maintenance of the irrigated agriculture, or your cost be elevated, seeking itself alternative with water use of the underground or even of drainage. Generally, these waters are not of good quality and they need to be well managed to avoid the degradation of the soils and damages to the plants. This work objectified evaluate the composition of lixiviate in four soils of Rio Grande do Norte, irrigated with waters of increasing levels of electric conductivity (EC) and sodium adsorption relation (SAR). This work aims to evaluate Assu/Mossoró, RN, agricultural production center soil degradation under irrigation with increasing electrical conductivity (EC) levels, and sodium adsorption rates (RAS), when cultivated with cantaloupe. The work was conducted in a greenhouse at the Environmental Sciences Department of Semi-Arid Rural Federal University. Four soil types, traditionally used for cantaloupe production, were used and irrigated with solutions corresponding to eight EC (EC = 100, 250, 500, 750, 1.250, 1.750, 2.250 and 3.000 ¿S/cm) and two SAR (SAR = 4 and 12) levels, as salinity treatments, corresponding to the irrigation waters used in the Northeast, with low sodification risk, especially in the studied area. So the experiment was a factorial arrangement of 4 x 8 x 2 (four soils, eight EC and two SAR), with three replicates, on a randomized block design. They were evaluated pH and EC, as well as cations and anions soluble of each lixiviate collected of the 10 days after transplanted of the dumb. The use of leaching solutions promoted salt leaching in four studied soils, mainly at Cambissolo and Neossolo.The increase in the concentration of the percolates solutions promoted larger losses of salts, which were crescent with the time of leachate.