@article{fdi:010052944,
  title = {{T}oxic levels of metals in {F}erralsols under natural vegetation and crops in {N}ew {C}aledonia},
  author = {{B}ecquer, {T}hierry and {Q}uantin, {C}. and {B}oudot, {J}.{P}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he chemistry of soil solutions and the potential toxicity of trace metals ({C}o, {C}r, {C}u, {N}i and {M}n) were investigated on soils formed on ultramafic rocks. {S}oil solutions were collected along a soil toposequence under natural vegetation and under a cropped field. {I}n the latter, metal speciation and species activity were computed with the {WHAM} 6 model. {T}otal element concentrations varied with the soil topographic position. {U}pslope, in well-drained soils, they were relatively small with mean concentrations of < 0.2 mu mol l(-1) for {C}o and {C}r and < 2 mu mol l(-1) for {N}i and {M}n. {D}ownslope, in temporarily waterlogged soils, concentrations reached 37 ({M}n), 5.6 ({N}i), 1.9 ({C}o) and 0.1 ({C}r) mu mol l(-1). {U}nder crops, {N}i, {M}n and {C}o concentrations were similar to those under natural vegetation, but {C}r concentration averaged 5 mu mol l(-1). {C}u concentration was close to 1 mu mol l(-1). {F}ree-ion species amounted to 53-71% of all species for {C}o, {N}i and {M}n but only 5% for {C}u. {C}r was almost entirely in the {C}r({VI}) form ({C}r{O}42-, {HC}r{O}4-). {T}he free-metal-ion activities were in the range 26-81% of the corresponding free-metal-ion concentration. {C}omparing our data with levels that are toxic to crops, {N}i and {C}r are potentially toxic in the well-drained and the poorly-drained soils. {I}n the latter, {C}o and {M}n are also potentially toxic. {B}oth the large concentration of metals and the chemical species in which they occur in solution could limit the use of the land for agricultural purpose.},
  keywords = {},
  booktitle = {},
  journal = {{E}uropean {J}ournal of {S}oil {S}cience},
  volume = {61},
  numero = {6},
  pages = {994--1004},
  ISSN = {1351-0754},
  year = {2010},
  DOI = {10.1111/j.1365-2389.2010.01294.x},
  URL = {https://www.documentation.ird.fr/hor/fdi:010052944},
}