Agronomic Practices for Improving Gentle Remediation of Trace Element-Contaminated Soils

Abstract

The last few decades have seen the rise of Gentle soil Remediation Options (GRO), which notably include in situ contaminant stabilization ("inactivation") and plant-based (generally termed "phytoremediation") options. For trace element (TE)-contaminated sites, GRO aim to either decrease their labile pool and/or total content in the soil, thereby reducing related pollutant linkages. Much research has been dedicated to the screening and selection of TE-tolerant plant species and genotypes for application in GRO. However, the number of field trials demonstrating successful GRO remains well below the number of studies carried out at a greenhouse level. The move from greenhouse to field conditions requires incorporating agronomical knowledge into the remediation process and the ecological restoration of ecosystem services. This review summarizes agronomic practices against their demonstrated or potential positive effect on GRO performance, including plant selection, soil management practices, crop rotation, short rotation coppice, intercropping/row cropping, planting methods and plant densities, harvest and fertilization management, pest and weed control and irrigation management. Potentially negative effects of GRO, e.g., the introduction of potentially invasive species, are also discussed. Lessons learnt from long-term European field case sites are given for aiding the choice of appropriate management practices and plant species.

Potential of Ranunculus acris L. for biomonitoring trace element contamination of riverbank soils: photosystem II activity and phenotypic responses for two soil series

“…For all soils, soil-pore waters were collected (three times 10 mL during weeks 16 and 17 to make a 30-mL sample) and kept at 4°C prior to TE analysis by ICP-AES (Varian liberty 200, Germany) and ICP-MS (Thermo X series 200, USA) at the INRA USRAVE laboratory (Villenave d'Ornon, France). Trace element concentrations in soil-pore water along the Jalle d'Eysines River and at the PHYTOSED Scale 1 platform were detailed by Marchand et al (2014) and Kidd et al (2014), respectively. The soil-soil-pore water partition coefficients [Kd TE (L kg −1 )=total soil TE concentration (mg kg −1 )/TE concentration in the soil-pore water (mg L −1 )] were calculated for three (Zn, Cd, and Cu) out of the four TE which exceeded both the French guideline values for dredged-sediment management and the inquiry threshold values for French soils on the soil series A and B.…”

Plant responses to a phytomanaged urban technosol contaminated by trace elements and polycyclic aromatic hydrocarbons

“…Conventional approaches to contaminated land risk management have focused on containment, cover, and removal to landfill (Cundy et al 2013). However, shifts are emerging towards sustainable practices within the remediation industry, with particular development of the phytotechnologies Mench et al 2010;Cundy et al 2013;Kidd et al 2015). Among them emerged notably in situ contaminant stab i l i z a t i o n ( Bi n a c t i v a t i o n^) a n d p l a n t -b a s e d (Bphytoremediation^) options (Cundy et al 2013;Kumpiene et al 2014;Kidd et al 2015).…”

“…However, shifts are emerging towards sustainable practices within the remediation industry, with particular development of the phytotechnologies Mench et al 2010;Cundy et al 2013;Kidd et al 2015). Among them emerged notably in situ contaminant stab i l i z a t i o n ( Bi n a c t i v a t i o n^) a n d p l a n t -b a s e d (Bphytoremediation^) options (Cundy et al 2013;Kumpiene et al 2014;Kidd et al 2015). The use of GRO aims at disrupting the pollutant-linkages (DEFRA 2012) either by controlling the source (e.g., extracting the contamination from the subsurface); managing the pathway(s) (e.g., preventing migration of contamination); and protecting the receptor(s) (e.g., planning or institutional controls to avoid sensitive land uses).…”

Soil Contamination and Human Health: A Major Challenge for Global Soil Security

“…A lot of efforts have been done for the last ten years to increase the efficiency of Trace Element remediation by testing different soil management practices, different crops under different soil conditions (Kidd et al, 2015). Further research and development are needed for remediating other kinds of contaminants and for increasing the knowledge on bioaugmentation techniques in order to improve the efficiency of these positive environmental balance technologies.…”