Cadmium Content of Wheat Grain from a Long‐Term Field Experiment with Sewage Sludge

• Published in: Journal of environmental quality Vol. 30; no. 5; pp. 1575 - 1580
• Main Authors: Chaudri, Amar M., Allain, Céline M.G., Badawy, S.H., Adams, Martin L., McGrath, Steve P., Chambers, Brian J.
• Format: Journal Article
• Language: English
• Published: Madison American Society of Agronomy, Crop Science Society of America, Soil Science Society 01.09.2001; Crop Science Society of America; American Society of Agronomy
• Subjects: Agriculture; Agronomy. Soil science and plant productions; Biological and medical sciences; Cadmium; Cadmium - analysis; Cadmium - pharmacokinetics; Conservation of Natural Resources; Cultivars; Fundamental and applied biological sciences. Psychology; Metals, Heavy - pharmacokinetics; Pore water; Sewage - chemistry; Sewage sludge; Soil and water pollution; Soil science; Soils; Tissue Distribution; Triticum - chemistry; Triticum - growth & development; Triticum aestivum; Wheat; Cadmium; Monocotyledones; Waste utilization; Grains; Pollutant behavior; Long term test; Sewage sludge; Cereal crop; Field experiment; Heavy metal; Trophic chain; Gramineae; Content; Angiospermae; Agricultural product; Cereal; Environment; Poison; Spermatophyta; Wheat; Triticum aestivum
• ISSN: 0047-2425; 1537-2537
• DOI: 10.2134/jeq2001.3051575x

ABSTRACT Grain Cd concentrations were determined in the wheat (Triticum aestivum L.) cultivars Soissons, Brigadier, and Hereward grown in 1994, 1996, and 1999, respectively, in soils of a long‐term field experiment to which sewage sludges contaminated with Zn, Cu, Ni, or Cr had previously been added. Soil pore water soluble Cd and free Cd2+ increased linearly with increasing total soil Cd (R2 = 0.82 and 0.84, respectively; P < 0.001). Similarly, soil pore water free Cd2+ increased linearly with increasing soil pore water soluble Cd (R2 = 0.98; P < 0.001). There was no evidence of a plateau in soil pore water Cd concentrations with increasing soil Cd concentrations. Grain Cd concentrations were significantly correlated with total soil Cd (P < 0.001), soil pore water Cd (P < 0.001), and free Cd2+ (P < 0.001). A slight curvilinear relationship between grain Cd and soil Cd was apparent, but there was no plateau, even at the maximum soil Cd concentration of about 2.7 mg kg−1 The relationship between soil pore water Cd and grain Cd was linear for all three cultivars. The slopes were in the order 1994 > 1996 > 1999, with more Cd being taken up into the grain by Soissons grown in 1994, and least by Hereward grown in 1999. For Soissons, Cd concentration in the grain greater than the EU limit (0.24 mg kg−1 dry wt.) occurred at soil Cd less than the current UK limit of 3 mg kg−1 for soils receiving sewage sludge. In contrast, for Brigadier and Hereward, grain Cd concentrations were near to and less than the EU limit, respectively, at soil Cd concentrations of 3 mg kg−1