Abstract
Heavy metal phytoextraction is a soil remediation technique which implies the optimal use of plants to remove contamination from soil. Plants must thus be tolerant to heavy metals, adapted to soil and climate characteristics and able to take up large amounts of heavy metals. Their roots must also fit the spatial distribution of pollution. Their different root systems allow plants to adapt to their environment and be more or less efficient in element uptake. To assess the impact of the root system on phytoextraction efficiency in the field, we have studied the uptake and root systems (root length and root size) of various high biomass plants (Brassica juncea, Nicotiana tabacum, Zea mays and Salix viminalis) and one hyperaccumulator (Thlaspi caerulescens) grown in a Zn, Cu and Cd contaminated soil and compared them with total heavy metal distribution in the soil. Changes from year to year have been studied for an annual (Zea mays) and a perennial plant (Salix viminalis) to assess the impact of the climate on root systems and the evolution of efficiency with time and growth. In spite of a small biomass, T. caerulescens was the most efficient plant for Cd and Zn removal because of very high concentrations in the shoots. The second most efficient were plants combining high metal concentrations and high biomass (willows for Cd and Zn and tobacco for Cu and Cd). A large cumulative root density/aboveground biomass ratio (LA/B), together with a relative larger proportion of fine roots compared to other plants seemed to be additional favourable characteristics for increased heavy metal uptake by T. caerulescens. In general, for all plants correlations were found between L A/B and heavy metal concentrations in shoots (r=0.758***, r=0.594***, r=0.798*** (P<0.001) for Cd, Cu and Zn concentrations resp.). Differences between years were significant because of variations in climatic conditions for annual plants or because of growth for perennial plants. The plants exhibited also different root distributions along the soil profile: T. caerulescens had a shallow root system and was thus best suited for shallow contamination (0.2 m) whereas maize and willows were the most efficient in colonising the soil at depth and thus more applicable for deep contamination (0.7 m). In the field situation, no plant was able to fit the contamination properly due to heterogeneity in soil contamination. This points out to the importance and the difficulty of choosing plant species according to depth and heterogeneity of localisation of the pollution.
Similar content being viewed by others
References
Atkinson D 2000 Root characteristics: why and what to measure. In Root Methods: A Handbook. Eds. A L Smit, A G Bengough, C Engels, M van Noordwijk, S Pellerin and S C van de Geijn. pp. 2–32. Springer-Verlag, Berlin, Heidelberg, Germany.
Baker A J M and Brooks R R 1989 Terrestrial higher plants which hyperaccumulate metallic elements – a review of their distribution, ecology and phytochemistry. Biorecovery 1, 81–126.
Bauhus J and Messier C 1999 Evaluation of fine root length and diameter measurements obtained using RHIZO image analysis. Agron. J. 91, 142–147.
Blaylock M J and Huang J W 2000 Phytoextraction of metals. In Phytoremediation of Toxic Metals Using Plants to Clean Up the Environment. Eds. I Raskin and B D Ensley. pp. 53–70. John Wiley and Sons Inc., NY.
Bennie A T P 1996 Growth and mechanical impedance. In Plant Roots, The Hidden Half. Eds. Y Waisel, A Eshel and U Kafkafi. pp. 453–470. Marcel Dekker Inc., NY.
Breckle S-W and Kahle H 1992 Effect of toxic heavy metals (Cd, Pb) on growth and mineral nutrition of beech (Fagus sylvatica L.). Vegetatio 101, 43–53.
Box J E 1996 Modern methods for root investigations. In Plant Roots, The Hidden Half. Eds. Y Waisel, A Eshel and U Kafkafi. pp. 193–237. Marcel Dekker Inc., NY.
Box J E and Ramseur E L 1993 Minirhizotron wheat root data: Comparison to soil core root data. Agron. J. 85, 1058–1060.
Campbell B D and Grime J P 1989 A new method of exposing developing root systems to controlled patchiness inmineral nutrient supply. Ann. Bot. 63, 395–400.
Chassot A, Stamp P and Richner W 2001 Root distribution and morphology of maize seedlings as affected by tillage and fertilizer placement. Plant Soil 231, 123–135.
Dickinson N M, Turner A P and Lepp N W 1991 How do trees and other long-lived plants survive in polluted environments? Funct. Ecol. 5, 5–11.
Eissenstat D M 1992 Costs and benefits of constructing roots of small diameter. J. Plant Nutr. 15, 763–782.
Eissenstat D M and Caldwell M M 1988 Seasonal timing of root growth in favourable microsites. Ecology 69, 870–873.
Ernst W H O 1996 Bioavailability of heavy metals and decontamination of soils by plants. Appl. Geochem. 11, 163–167.
Eshel A and Waisel Y 1996 multiform and multifunction of various constituents of one root system. In Plant Roots, The Hidden Half. Eds. Y Waisel, A Eshel and U Kafkafi. pp. 175–192. Marcel Dekker Inc., NY.
FAC (Eidgenössische Forschungsanstalt für Agrikulturchemie und Umwelthygiene) 1989 Methoden für die Bodenuntersuchungen. Schriftenreihe der FAC 5, Bern-Liebefeld, Switzerland. 267 pp.
FAL (Eidgenössische Forschungsanstalt für Agrarökologie und Landbau) 1998 Manuel pour l'analyse des sols, des plantes et de l'eau de percolation lysimétrique. Les Cahiers de la FAL 27, Zürich-Reckenholz, Switzerland. 227 pp.
Fitter A H 1987 An architectural approach to the comparative ecology of plant root systems. New Phytol. 106 (Suppl.), 61–77.
Fitter A H 1996 Characteristics and functions of root systems. In Plant Roots, The Hidden Half. Eds. Y Waisel, A Eshel and U Kafkafi. pp. 1–20. Marcel Dekker Inc., NY.
Fitter A H and Stickland T R 1991 Architectural analysis of plant root systems. 2. Influence of nutrient supply on architecture in contrasting plant species. New Phytol. 118, 383–389.
Flury M, Flühler H, Jury W A and Leuenberger J 1994 Susceptibility of soils to preferential flow of water: a field study. Water Resour. Res. 30, 1945– 1954.
Flury M and Flühler H 1995 Tracer characteristics of Brilliant Blue FCF. Soil Sci. Soc. Am. J. 59, 22–27.
Foch H D 1962 Roots and top growth of corn. Agron. J. 54, 49–52.
Hagenmeyer J and Breckle S-W 1996 Growth under trace element stress. In Plant Roots, The Hidden Half. Eds. Y Waisel, A Eshel and U Kafkafi. pp. 415–433. Marcel Dekker Inc., NY.
Hesske S, Schaerli M, Tietje O and Scholz R 1998 Zum Umgangmit Schwermetallen im Boden: Falldossier Dornach. Pabst Science Publishers, Lengerich, Germany. 145 pp.
Kayser A, Wenger K, Keller A, Attinger W, Felix H R, Gupta S K and Schulin R 2000 Enhancement of phytoextraction of Zn, Cd and Cu from calcareous soil: the use of NTA and sulphur amendments. Environ. Sci. Technol. 34, 1778–1783.
Kirkegaard J A, So H B and Troedson R J 1992 The effect of soil strength on the growth of pigeonpea radicles and seedlings. Plant Soil 140, 65–74.
Kirkham M B, Grecu S J and Kanemasu E T 1998 Comparison of minorhizotrons and the soil– water-depletion method to determine maize and soybean root length and depth. Eur. J. Agron. 8, 117–125.
de Kroon H and Hutchings M J 1995 Morphological plasticity in clonal plants: the foraging concept reconsidered. J. Ecol. 83, 143–152.
Marschner H 1995 Mineral Nutrition of Higher Plants. Academic Press Ltd., London.
McGrath S P 1998 Phytoextraction for soil remediation. In Plants that Hyperaccumulate Heavy Metals. Ed. R R Brooks. pp. 261–287. CAB International, Oxon, UK.
Nye P H and Tinker P B 1977 Solute movement in the soil-root system. Blackwell, Oxford, UK.
OIS (Swiss Ordinance Relating to Impacts on the Soil) 1st July 1998, SR 814.12. Switzerland.
Palazzo A J and Lee C R 1997 Root growth and metal uptake of plants grown on zinc-contaminated soils as influenced by soil treatment and plant species. In Extended Abstracts of the 4th International Conference on the Biogeochemistry of Trace Elements. pp 441–442. 23– 26 June 1997, Berkeley, CA.
Polomski J and Kuhn N 1998 Wurzelsysteme. Eidgenössische Forschungsanstalt für Wald, Schnee und Landschaft, Birmensdorf. Paul Haupt, Bern, Switzerland. 290 pp.
Reeves R D and Baker A J M 2000 Metal-accumulating plants. In Phytoremediation of Toxic Metals using Plants to Clean Up the Environment. Eds. I Raskin and B D Ensley. pp. 193–230. John Wiley and Sons Inc., NY.
Robinson B H, Leblanc M, Petit D, Brooks R R, Kirkman J H and Gregg P E H 1998 The potential of Thlaspi caerulescens for phytoremediation of contaminated soils. Plant Soil 203, 47–56.
Sauerbeck D 1989. Der Transfer von Schwermetallen in die Pflanze: In Beurteilung von Schwermetallkontaminationen im Boden. DECHEMA. pp. 281–316. Fachgespräche Umweltschutz. Stuttgart am Mainz, Germany.
Schwartz C, Morel J-L, Saumier S, Whiting S N and Baker A J M 1999 Root architecture of the Zn-hyperaccumulator plant Thlaspi caerulescens as affected by metal origin, content and localization in soil. Plant Soil 208, 103–115.
SMA (Schweizerische Meteorologisches Zentralanstalt) 1992 Klimatologie des Schweiz. Zürich, Schweizerische Meteorologisches Zentralanstalt.
Schnoor J L, Licht L A, McCutcheon S C, Wolfe N L and Carreira L H 1995 Phytoremediation of organic and nutrient contaminants. Environ. Sci. Technol. 29, 318A–323A.
Schnoor J L 1997 Phytoremediation. Technology Evaluation Report TE–98-01. GWRTAC E Series, Pittsburgh, PA.
Smucker A J M, McBurney S L and Srivastava A K 1982 Quantitative separation of roots from compacted soil profiles by hydropneumatic eltration system. Agron. J. 74, 500–503.
SPSS Inc. 1998 Systat Version 8. Chicago, IL.
Taub D R and Goldberg D 1996 Root system topology of plants from habitats differing in soil resource availability. Funct. Ecol. 10, 258–264.
Upchurch D R and Ritchie J T 1984 Battery-operated color video camera for root observations in minirhizotrons. Agron. J. 76, 1015–1017.
Vangronsveld J and Cunningham S D 1998 Chapter 1. Introduction to the concept. In J. Metal-contaminated Soils. Eds. J Vangronsveld and S D Cunningham. pp. 1–16. Springer NY.
Whiting S N, Leake J R, McGrath S P and Baker A J M 2000 Positive response to Zn and Cd by roots of the Zn and Cd hyperaccumulator Thlaspi caerulescens. New Phytol. 145, 199–210.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Keller, C., Hammer, D., Kayser, A. et al. Root development and heavy metal phytoextraction efficiency: comparison of different plant species in the field. Plant and Soil 249, 67–81 (2003). https://doi.org/10.1023/A:1022590609042
Issue Date:
DOI: https://doi.org/10.1023/A:1022590609042