Heavy metals phytoextraction from heavily and moderately contaminated soil by field crops grown in monoculture and crop rotation

Abstract

Abstract:The uptake of Pb, Cd, Zn and biomass production of the plants Brassica juncea v. Opaleska, Triticale hexaploides var. Gabo and Helianthus annuus v. Maritza were observed in a field (trial) and a pot experiments during four years. The plants were grown in monoculture variants and also in crop rotation. The field experiment (plots about 1 × 1 m) was set up in heavily contaminated Haplic Fluvisol in the Litavka River alluvium. Pb, Cd, and Zn phytoextraction from the identical Haplic Fluvisol and Haplic Cambisol less contaminated mainly by atmospheric deposition was observed in the pot experiment. The application of 0.2 g EDTA (ethylenediaminetetraacetic acid)/kg and 1 g citric acid/kg into the soils of field (250 kg of soil/m 2 plot) and pot (6 kg of soil/pot) experiments was realized. The comparison was accomplished between natural phytoextraction efficiency of B. juncea, H. annuus, and T. hexaploides. Crop rotation with and without chemical induction was tested. EDTA application had an immediate strong mobilization effect on the elements tested in both experiments and both soils. In the pot experiment, Pb, Cd, and Zn were more mobilized in Cambisol with initial lower mobile contents of elements in comparison with Fluvisol. The highest mobilization by EDTA was achieved for Pb. Strong Pb mobilization in Cambisol after EDTA addition resulted in a high Pb uptake and translocation from the roots of B. juncea into the shoots. EDTA application increased Pb phytoextraction by harvested B. juncea. Naturally grown H. annuus proved the high phytoextraction efficiency for Cd and Zn in the experiment. The assumed effect of the cultivation method, i.e. crop rotation vs. Monoculture, was not statistically proved in our experiments.

Phytoremediation Mechanisms of Heavy Metal Contaminated Soils: A Review

“…The process of absorption of pollutants by plants and volatilization into the atmosphere by the foliar system processes, it cannot be expected to clean up the soil only by one plant species used exclusively in monoculture [114]. Grasses, with their highly developed root system, can stabilize the soils and reduce erosion, while legumes can add nitrogen to the soil, preparing the establishment of other plant species typical of later stages of succession [115]- [117].…”

Evaluation Of The Content Of Trace Elements In The Aerial And Underground Biomass Of Perennial Grasses Of The Genus Miscanthus

“…elements in soil is parent material; they are released and made available to plants and, usually in such quantities (form), they pose no threat to living organisms [3][4][5]. A total amount of trace elements in soil exceeding the norms is most often due to pollution of the environment with exhaust gases, industrial dusts or crop protection chemicals [5][6][7].…”

Thallium uptake/tolerance in a model (hyper)accumulating plant: Effect of extreme contaminant loads

“…An advantage of phytoextraction processes using the hyperaccumulating plants could be the natural selection of trace elements (Čechmánková et al 2011;Corzo Remigio et al 2020), though, the Tl/element transfer under the laboratory trial has several limitations, such as the number of suitable plants with a high accumulation potential tolerance for specific soil/climatic conditions. The bioavailability of Tl in soil depends on the specific sorption, mainly onto specific Mn oxide, birnessite (δ-MnO 2 ) and illite [(K,H 3 O)Al 2 (Al,Si) 4 O 10 (OH) 2 ], being probably the most important Tl scavengers and the general stability of Tl-host phase (Al-Najar et al 2003;Vaněk et al 2013;Grösslová et al 2015).…”