Highly charged swelling mica reduces Cu bioavailability in Cu-contaminated soils.
This is the first test of a highly charged swelling mica's (Na-2-mica) ability to reduce the plant-absorbed Cu in Cu-contaminated soils from Chile. Perennial ryegrass (Lolium perenne L.) was grown in two acid soils (Sector 2: pH 4.2, total Cu = 172 mg Cu kg(-1) and Sector 3: pH 4.2, total Cu = 112 mg Cu kg(-1)) amended with 0.5% and 1% (w/w) mica, and 1% (w/w) montmorillonite. At 10 weeks of growth, both mica treatments decreased the shoot Cu of ryegrass grown in Sector 2 producing shoot Cu concentrations above 21-22 mg Cu kg(-1) (the phytotoxicity threshold for that species), yet the mica treatments did not reduce shoot Cu concentrations when grown in Sector 3, which were at a typical level. The mica treatments improved shoot growth in Sector 3 by reducing free and extractable Cu to low enough levels where other nutrients could compete for plant absorption and translocation. In addition, the mica treatments improved root growth in both soils, and the 1% mica treatment reduced root Cu in both soils. This swelling mica warrants further testing of its ability to assist re-vegetation and reduce Cu bioavailability in Cu-contaminated surface soils.
Stuckey
Jason W
JW
Department of Crop and Soil Sciences, The Pennsylvania State University, 116 ASI Building, University Park, PA 16802, USA.
Neaman
Alexander
A
Ravella
Ramesh
R
Komarneni
Sridhar
S
Martínez
Carmen Enid
CE
D000538:Aluminum Silicates; D018533:Biomass; D000077215:Clay; D003300:Copper / Q000032:analysis; D052918:Environmental Restoration and Remediation / Q000379:methods*; D007220:Industrial Waste; D008129:Lolium / Q000737:chemistry / Q000254:growth & development*; D018517:Plant Roots / Q000737:chemistry; D018520:Plant Shoots / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis; D013997:Time Factors
D000538:Aluminum Silicates; D007220:Industrial Waste; D012989:Soil Pollutants; D003300:Copper; D000077215:Clay; C011934:mica