Resumen

LEAL, Isaac Gomes et al. Use of Atriplex nummularia and gypsum for phytoremediation of saline-sodic soil. Rev. Bras. Ciênc. Solo [online]. 2008, vol.32, n.3, pp. 1065-1072. ISSN 0100-0683.  http://dx.doi.org/10.1590/S0100-06832008000300015.

The cultivation of Atriplex nummularia on saline-sodic soils is economically attractive because it can be used as a forage crop as well as in landscape projects. The potential of Atriplex nummularia for phytoextraction of Na⁺ from a saline-sodic soil irrigated with saline water was evaluated. Additionally, gypsum was tested for improving phytoremediation. The experiment was set up as a randomized block design, in a 2 x 3 factorial scheme. The treatments consisted of: no gypsum and 50 % of the regularly recommended gypsum dose, and three salinity levels of irrigation water: C₁ = 175 μS cm ^-1; C₂ = 500 μS cm ^-1; C₃ = 1,500 μS cm ^-1. The Na concentration in plant tissues and soil were evaluated 40, 70, 100 and 130 days after A nummularia transplanting. The results showed that there was a 96 % increase in root dry matter as a result of gypsum application. Sodium accumulation in shoots increased significantly in the third (90.1 g kg^-1) and fourth (109.7 g kg^-1) sampling period. This effect was magnified by gypsum application. After 100 days, the soil Na⁺ content had decreased by 31 and 26 %, with and without gypsum addition, respectively. Our results indicate that A. Nummularia is a Na⁺ accumulator species. Gypsum was effective as a phytoextraction enhancer. A. nummularia irrigation aiming at Na phytoremediation is possible with saline water varying from 175 to 1,500 μS cm^-1.

Palabras llave : salinity; sodicity; phytoextraction; halophyte; gypsum.