Phytoremediation: Enhanced cadmium (Cd) accumulation by organic manuring, EDTA and microbial inoculants (Azotobacter sp., Pseudomonas sp.) in Indian mustard (Brassica juncea L.)

Abstract

Phytoremediation is an approach designed to extract excessive heavy metals from contaminated soils through plant uptake. Cadmium (Cd) is among the elements most toxic to living organisms. Health hazards associated with the lethal intake of Cd include renal (kidney) damage, anaemia, hypertension and liver damage. A greenhouse experiment was carried out with Indian mustard (Brassica juncea) grown on artificially spiked soil (100 μg Cd g−1) with EDTA (2 mmol kg−1 in 5 split doses), FYM, vermicompost (VC) and microbial inoculants (MI) such as Azotobacter sp. and Pseudomonas sp. The growth of Brassica juncea L. was better in soil amended with FYM or VC as compared to unamended Cd-polluted soil. Growth was slightly suppressed in EDTA-treated soil, whereas it was better after treatment with MI. The application of FYM and VC increased the dry matter yield of Indian mustard either alone or in combination with microbial inoculants, while that of EDTA caused a significant decrease in the biomass of Indian mustard. The application of microbial inoculants increased the dry matter yield of both the roots and shoots, but not significantly, because MI shows greater sensitivity towards cadmium. The maximum cadmium concentration was observed in the EDTA +MI treatment, but Cd uptake was maximum in the VC + MI treatment. The Cd concentration in the shoots increased by 120% in CdEDTA over the Cd100 treatment, followed by CdVC (65%) and CdFYM (42%) in the absence of microbial inoculants. The corresponding values in the presence of MI were 107, 51 and 37%, respectively. A similar trend was also observed in the roots in the order CdEDTA+M > CdVC+M > CdFYM+M>Cd100+M.MI caused an increase in Cd content of 5.5% in the roots and 4.1% in the shoots in the CdEDTA+M treatment compared with the CdEDTA treatment. FYM, VC and EDTA also increased Cd uptake significantly both in the shoots and roots with and without microbial inoculants.The results indicated that Vermicompost in combination with microbial inoculants is the best treatment for the phytoremediation of Cd-contaminated soil by Indian mustard, as revealed by the Cd uptake values in the shoots: CdVC+M (2265.7 μg/pot) followed by CdEDTA+M (2251.2 μg/pot), CdFYM+M (1485.7 μg/pot) and Cd100+M (993.1 μg/pot).

Fruit Quality of Tomato Affected by Single and Combined Bioeffectors in Organically System

“…It was found only in the pot experiment that the abundance of microorganisms is increasing with the plant age. The connection of microbial presence and activity with plantnecessity was already demonstrated among serious environmental stress conditions in several previous publications (Vivas et al, 2006;Panwar et al, 2011;Domonkos et al, 2013). Testing the MPN abundance of microorganisms in the tomato plant rhizosphere, differences among the used treatments were not found significantly in our study.…”

Phytoremediation: A novel green technology to restore soil health

“…FYM, Vermicompost and EDTA also increased the Cd uptake significantly with and without microbial inoculates in the shoots and roots. The results indicated that Vermicompost in combination with bioinoculants is a better solution for the phytoremediation of Cd by Indian mustard from Cd-contaminated soil, giving the highest uptake value in the shoot in the Cd VC+M treatment (2265.7 µg/pot), followed by Cd EDTA+M (2251.2 µg/pot), Cd FYM+M (1485.7 µg/pot) and Cd 100+M (993.1 µg/pot) (Panwar, 2010). Simon et al (2008) reported that crop species removed considerable amounts of cadmium from solution containing Cd after 48 hours of exposure.…”

Influence of graded EDTA applications on mobilization and translocation of trace elements—a soil column experiment

“…Many studies have shown increased plant availability of various heavy metals following application of EDTA or other chelating agents such as N‐(hydroxyethyl)‐ethylenediaminetriacetic acid (HEDTA), nitrilotriacetic acid (NTA) or diethylenetriaminepentaacetic acid (DTPA) ( e.g ., Chen and Cutright , ; Hseu et al, ). As such, the phytoremediation potential of plants can be improved substantially by using chelating agents ( Blaylock et al, ; Vassil et al, ; Grčman et al, ; Piechalak et al, ; Epelde et al., ; Panwar et al, ). Many studies have focused on lead (Pb) in relation to phytoremediation and EDTA application, as it is one of the most important metallic soil contaminants ( Blaylock et al, ; Saifullah et al, ).…”