Growth and differential salinity reduction between Portulaca oleracea and Eichhornia crassipes in experimental hydroponic units.

We evaluated the salinity reduction of the experimental saline solutions through ion uptake capacity of two plant species, purslane (PU) (Portulaca oleraceae) and water hyacinth (WH) (Eichhornia crassipes). These species were grown in experimental hydroponic units simulating a floating system. The hydroponic system contained treatments with three nutrient solutions identified as A1, A2, and A3 composed of fixed concentrations of macro and micronutrients to which three different concentrations of sodium chloride had been added. After the experimental period, physicochemical and volume changes in the saline nutrient solutions were evaluated. The relative growth rate results were similar for both plant species, but with lower consumption of hydroponic nutrient solutions by PU. Despite higher solution volume loss, regardless of the nutrient solution applied, WH had greater weekly estimated potential of reduction of macronutrients (calcium and magnesium; >50%); however, PU showed the best weekly potential reduction of sodium (36%) with solution A2. Therefore, both plants present potential to be used for salinity reduction in the natural conditions.