%0 Journal Article
%T Organic Matter and Barium Absorption by Plant Species Grown in an Area Polluted with Scrap Metal Residue
%A Cleide Aparecida Abreu
%A Mariana Cantoni
%A Aline Ren¨¦e Coscione
%A Jorge Paz-Ferreiro
%J Applied and Environmental Soil Science
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/476821
%X The effect of organic matter addition on Ba availability to Helianthus annuus L., Raphanus sativus L., and Ricinus communis L. grown on a Neossolo Lit¨®lico Chernoss¨®lico fragment¨¢rio (pH 7.5), contaminated with scrap residue was evaluated. Four rates (0, 20, 40, and 80£¿Mg ha£¿1, organic carbon basis) of peat or sugar cane filter, with three replicates, were tested. Plant species were grown until the flowering stage. No effect of organic matter addition to soil on dry matter yield of oilseed radish shoots was observed, but there was an increase in sunflower and castor oil plant shoots when sugar cane filter cake was used. The average Ba transferred from roots to shoots was more than 89% for oilseed radish, 71% for castor oil plants, and 59% for sunflowers. Organic matter treatments were not efficient in reducing Ba availability due to soil liming. 1. Introduction Accumulation of some chemical elements in the environment is of great concern because they can reach concentrations that may cause risks to human health and to the environment. Their concentration in soils depends on lithogenic and pedogenic processes, but also on anthropogenic activities. Soil pollution is a serious problem in many countries around the world. In S£¿o Paulo State, Brazil, since 2002, when the first survey was performed by the local environmental agency, more than 1600 contaminated areas have been identified [1]. The extensive industrial use of barium (Ba) adds up to the release of Ba in the environment and, as a result, Ba concentrations in air, water, and soil may be higher than naturally occurring concentrations on many locations [2¨C5]. Recently, it was observed that successive sewage sludge applications increased soil Ba concentration and accumulation in maize plants grown in the State of S£¿o Paulo [6]. Some research has shown probable Ba toxicity in plants, but such studies were short term and performed in nutrient solution [7, 8]. Ba is an alkaline earth element which occurs as a trace metal in igneous and sedimentary rocks. In nature it occurs mainly as low soluble minerals such as barite (BaSO4) and witherite (BaCO3). Ba solubilization and, consequently, the release of Ba2+ ions may occur under specific conditions. It has been shown to happen in acidic conditions [9], in the absence of oxygen, or even due to microbial action [10¨C13]. In contrast, Ba precipitates as a sulfate and/or carbonate salt in neutral or basic pH conditions. Therefore, the mobility of Ba is negligible in neutral or basic pH conditions, thus, reducing the risks of leaching and harmful health effects.
%U http://www.hindawi.com/journals/aess/2012/476821/