Evaluation of lead uptake of co-planting phytoextractor species (Bidens pilosa, Tagetes minuta and Brassica juncea) with Lettuce.

VERGARA CID, C.; SALAZAR, M.J.; PIGNATA, M.L.; RODRIGUEZ, J.H.

Workshop; Applications of Synchrotron Radiation for Environmental and Earth Sciences- Air, Water, Soil, Life.; 2014

Whether co-planting can reduce the impacts of lead (Pb) on crops in agroecosystems has not been well understood. The interaction of root exudates and rhizosphere among different plant species may facilitate nutrient and metal uptake between the co-planted species1. Co-planting represents a promising phytoremediation strategy to produce safe crops while soils being remediated. In this work we performed a pot experiment (under controlled conditions) in order to compare co-planting Pb uptake by lettuce (Lactuca sativa) in combination with accumulator species (Bidens pilosa, Tagetes minuta and Brassica juncea) vs. monocropping of each species. Plants were grown in soils with low, medium and high Pb levels. Soils were collected from lead polluted fields due to the presence of a smelter in the locality of Bouwer, Argentina. Plants were separated into roots, shoots and leaves and digested for heavy metal measurements. Lead and other metals were analyzed by TXRF in LNLS in Campinas, Brazil. In most cases, we found that Pb and others metals uptake were higher in the co-planting treatment than in monocropping. These results are not desirable for lettuce, since it consumption represents a threat to health. Consequently, another phytoremediation co-planting combination should be tested in order to allow safe crop production and remediation of soils.