Phytomanagement of a metal-contaminated agricultural soil with Sorghum bicolor near the former Pb/Zn Metaleurop Nord smelter
Phytomanagement d'un sol agricole contaminé par des métaux avec Sorghum bicolor près de l'ancienne fonderie de Pb/Zn Metaleurop Nord
Résumé
Lignocellulosic energy crops matter due to their ability to grow on contaminated and degraded soils, producing biomass for biofuels and thereby reducing the pressure on the limited arable lands. Sorghum bicolor (L.) Moench can potentially produce a high biomass suitable for bioethanol, renewable gasoline, diesel, and sustainable aircraft fuel production on contaminated soils, despite adverse environmental conditions (e.g. drought) while phytoextracting relevant amounts of Cd, Pb and Zn. This field study aimed at assessing the S. bicolor growth on a metal-contaminated (11 mg Cd, 536 mg Pb and 955 mg Zn kg -1 ) agricultural soil amended with humic/fulvic acid alone (HFA) and paired with arbuscular mycorrhizae fungi (HFAxAMF). The 2-year field trial consisted of three treatments in triplicates: control (C), HFA and HFAxAMF. After harvest, the shoot dry weight (DW) yield, ionome, and metal uptake of S. bicolor and the 0.01M Ca(NO3)2-extractable soil Cd, Pb and Zn concentrations were annually determined. The HFA and HFAxAMF treatments did not significantly affect the shoot DW yield and metal uptake. Sorghum produced an average of 12.4 t DW ha -1 year -1 despite experiencing a severe drought season in year 1. Its growth contributed to decrease 0.01 M Ca(NO3)2-extractable soil Cd, Pb and Zn concentrations by 95%, 73% and 95%, respectively, in year 2. The annual shoot Cd, Pb and Zn removals averaged 0.14, 0.20 and 1.97 kg ha -1 , respectively. This evidenced S. bicolor as a relevant plant species for phytomanaging a large area with metal-contaminated soil, such as those near the former Pb/Zn Metaleurop Nord smelter, amidst ongoing climate change.
Origine | Fichiers produits par l'(les) auteur(s) |
---|