Root development of non-accumulating and hyperaccumulating plants in metal-contaminated soils amended with biochar.
Biochar may be used as an amendment in contaminated soils in phytoremediation processes. The mechanisms controlling plant metal uptake in biochar-amended soils remain however unclear. This work aimed at evaluating the influence of biochar on root development and its consequence on plant metal uptake, for two non-hyperaccumulating plants (Zea mays and Lolium perenne) and one hyperaccumulator of Cd and Zn (Noccaea caerulescens). We conducted rhizobox experiments using one acidic and one alkaline soil contaminated with Cd, Pb and Zn. Biochar was present either homogeneously in the whole soil profile or localized in specific zones. A phenomenon of root proliferation specific to biochar-amended zones was seen on the heterogeneous profiles of the acidic soil and interpreted by a decrease of soil phytotoxicity in these zones. Biochar amendments also favored root growth in the alkaline soil as a result of the lower availability of certain nutrients in the amended soil. This increase of root surface led to a higher accumulation of metals in roots of Z.mays in the acidic soil and in shoots of N. caerulescens in the alkaline soil. In conclusion, biochar can have antagonist effects on plant metal uptake by decreasing metal availability, on one hand, and by increasing root surface and inducing root proliferation, on the other hand.
Université de Lorraine, Laboratoire Sols et Environnement, UMR 1120, 2, avenue de la Forêt de Haye, TSA 40602, 54518 Vandœuvre-lès-Nancy cedex, France; INRA, Laboratoire Sols et Environnement, UMR 1120, 2, avenue de la Forêt de Haye, TSA 40602, 54518 Vandœuvre-lès-Nancy cedex, France.
Frédéric
F
Rees
Université de Lorraine, Laboratoire Sols et Environnement, UMR 1120, 2, avenue de la Forêt de Haye, TSA 40602, 54518 Vandœuvre-lès-Nancy cedex, France; INRA, Laboratoire Sols et Environnement, UMR 1120, 2, avenue de la Forêt de Haye, TSA 40602, 54518 Vandœuvre-lès-Nancy cedex, France.
Thibault
T
Sterckeman
Université de Lorraine, Laboratoire Sols et Environnement, UMR 1120, 2, avenue de la Forêt de Haye, TSA 40602, 54518 Vandœuvre-lès-Nancy cedex, France; INRA, Laboratoire Sols et Environnement, UMR 1120, 2, avenue de la Forêt de Haye, TSA 40602, 54518 Vandœuvre-lès-Nancy cedex, France. Electronic address: jean-louis.morel@univ-lorraine.fr.
Jean Louis
JL
Morel
D001673:Biodegradation, Environmental; D002606:Charcoal / Q000737:chemistry*; D019684:Magnoliopsida / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism*; D008670:Metals / Q000302:isolation & purification / Q000378:metabolism* / Q000633:toxicity; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism*; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000302:isolation & purification / Q000378:metabolism / Q000633:toxicity
D008670:Metals; D012987:Soil; D012989:Soil Pollutants; C540010:biochar; D002606:Charcoal
Biochar; Lolium perenne; Metal; Noccaea caerulescens; Rhizobox; Zea mays