Desenvolvimento de Enterolobium contortisiliquum em solos contaminados de Santo Amaro na Bahia, associado a composto orgânico

Abstract

The Enterolobium contortisiliquum is a leguminous tree used for the reforestation of degraded areas and promising in the rehabilitation of soils with excess of heavy metals. The recovery of these areas usually have high cost, using alternative techniques of phytoremediation and bioremediation that rely ona community of plants and soil microorganisms. This study aimed to evaluate the initial development of E. contortisiliquum grown in a substrate composed of organic compound and soil contaminated with heavy metals. The experiment was conducted under 01controlled conditions, in nursery, in a completely randomized design with a 3x4 factorial design. Soils collected were tested at 50, 100 and 150 meters distance from the old Pb factory of Santo Amaro, in four proportions of soil and compost (0: 100, 50:50, 30:70 and 100: 0 v / v ), respectively, with 10 replicates. After 90 days were evaluated plant height (H), diameter (D), dry weight of shoot (MSPA), root dry mass (MSR), total dry matter (MST), chlorophyll (CLT), fresh weight of nodules ( PFN) and number of nodes (NN) were evaluated at 90 days after sowing and given the quality score of Dickson (IQD). The 50:50 v/v combination of soil and organic compound provided the best development of the seedlings, presenting 0.69 mm plant-1 D and H 36.6 cm plant-1. For the MSPA and MST were estimated maximum values of 6.44 g plant-1 and 9.38 g plant-1 in the proportions of 45:55 and 46:54 (solo 100 m away from the factory and organic compound), respectively. It was found that the seedlings grown in a mixture of organic compounds and soil contaminated with heavy metals are capable of nodulation with native soil bacteria. It is recommended to use the 50:50 v/v ratio of organic compound and contaminated soil to obtain seedlings with higher quality Dickson index.