Growth capacity, nodulation and phytoremediation potential for Stizolobium aterrimum in boron soils contaminated

Abstract

The soil contamination by heavy metals is a problem that has long worried the population, and increasingly has increased the number of contaminated sites due to the large increase of industrial activities that use these records for finishing processes. The major issue is that not all heavy metal is purely toxic, and several micronutrients are heavy metals, such as copper (Cu2 +) and boron (B) which is part of enzymes involved in oxidation-reduction reactions. This element may have increased their concentration in the soil due to human activities and also by excessive use of chemical fertilizers and pesticides. According to CETESB (2005) there is no B concentrations in soil indicating the levels of prevention and intervention; to water bodies, the values for intervention are 500 ¼g.L-1. Boron levels above 3,0 mg dm-3 already indicate toxic effects in many plants, and the major contributions of B in the environment occur through anthropogenic. An environmentally friendly alternative is phytoremediation, which are used tolerant plants to heavy metal removal or stabilization of the contaminant in the soil. The specie Stizolobium aterrimum is a herbaceous legume, which has favorable characteristics mentioned above, is also used as green manure in agricultural systems, and has been characterized as tolerant to heavy metal lead (Pb) and moderately tolerant to contamination by copper (Cu). Thus, the main objective of this study is to characterize tolerance and phytoremediation potential of S. aterrimum boron potential application for this plant as phytoremediation.