Analysis of the Ability of Marsh Samphire (Salicornia europaea) to Extract Environmentally Relevant Elements from Different Culture Media: Contribution of Biochar to Plant Nutrition and Growth

Abstract

Soil salinity is considered one of the major global challenges that agricultural production is currently facing. This condition, together with the increasing contamination with emerging pollutants, poses a serious risk for global food security. As efforts are made to develop nature-based solutions, bioremediation strategies have been implemented to harness different living organisms and mitigate environmental pollution. Halophytes grow in highly saline environment and can be the solution to valorize salt-degraded areas where other crops cannot grow. The aim of this work is to evaluate the physiological response of Salicornia europaea grown under different conditions and its potential to extract sodium (Na) and copper (Cu) from different culture media. Different experiments were conducted with S. europaea cultivated in hydroponics and in substrate with and without biochar including different Cu (0, 5 and 10 mg L-1 CuCl2) and Na (7.5 and 15 g L-1 NaCl) concentrations. The growth in hydroponic media under different salinities reveals that this halophyte can extract up to 80% and 55% of the initial Na content when growing at 7.5 g L-1 and 15 g L-1 NaCl, respectively. In addition, S. europaea tolerates high Cu concentration, accumulating up to 1.61 mg g-1 DW in roots when exposed to 10 mg L-1 CuCl2 and 7.5 g L-1 NaCl. Plants grown in substrate show a different behavior, being even more tolerant to higher Cu concentrations. In addition, the presence of biochar in the substrate improves plant growth and provides a greater quantity of micronutrients. These results show the potential of S. europaea to be used in the phytoremediation process.