Cu fractions, mobility and bioavailability in soil-wheat system after Cu-enriched livestock manure applications

• Published in: Chemosphere (Oxford) Vol. 82; no. 2; pp. 215 - 222
• Main Authors: Guan, T.X., He, H.B., Zhang, X.D., Bai, Z.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 2011; Elsevier
• Subjects: aerial parts; animal manures; Applied sciences; bioaccumulation; Bioavailability; copper; Copper - analysis; Copper - chemistry; Copper - metabolism; crops; ecotoxicology; Exact sciences and technology; fertilizer rates; Fertilizers - analysis; Fractions; heavy metals; Livestock manure; Manure - analysis; Mobility; Pentetic Acid - chemistry; Pentetic Acid - metabolism; Plant Roots - metabolism; Pollution; Refuse Disposal; risk; roots; soil; Soil - chemistry; Soil Pollutants - analysis; Soil Pollutants - chemistry; Soil Pollutants - metabolism; soil pollution; Soil-wheat system; spatial distribution; toxicity; Triticum - metabolism; Triticum aestivum; waste disposal; wheat; DTPA; Cu; Livestock manure; Mobility; Bioavailability; Soil-wheat system; Fractions; Monocotyledones; Organic matter; Toxicity; Organic fertilization; Soil pollution; Triticum; Absorption; Gramineae; Angiospermae; Agriculture; Copper; Sensitivity analysis; Grains; Pollutant behavior; Mollisols; Waste disposal; Heavy metal; Pot experimentation; Trace element; Soils; Environment impact; Spermatophyta; Livestock; Animal waste; Copper sulfate
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2010.10.018

Fertilization of crops with livestock manure (LM) is a common waste disposal option, but repeated application of LM containing high concentrations of heavy metals such as Cu could lead to crop toxicity and environmental risk. To examine the Cu availability and uptake by wheat in a Mollisol affected by Cu-enriched LM, pot experiments were conducted. LM (376
mg
kg
−1 Cu originally) was spiked with different concentrations of Cu (0, 100, 200, 400, 600 and 800
mg
kg
−1 soil, added as CuSO
4) to simulate soil Cu contamination by LM application. The results indicated that Cu was predominately distributed in organic bound fraction, while the most drastic increase was found in reducible fraction. Acid-extractable fraction played a more important role than other fractions in controlling the mobility and bioavailability of Cu. DTPA-extractable Cu may overestimate the Cu bioavailability since DTPA solution could extract soluble and part of stable forms. The application of LM at 1% level significantly decline the Cu mobility, but that at 3% level exhibited the opposite effect.
Although the quantities of Cu in wheat was very low compared with the accumulation in soil, Cu concentrations in roots increased evidently from 12 to 533
mg
kg
−1 and that in aerial parts were in a narrow range from 12.1 to 32.7
mg
kg
−1, indicating the more sensitivity of roots to the Cu toxicity. The Cu concentrations in grains after 3% manure application did not approach the threshold for Cu toxicity (<20
mg
kg
−1) even at higher Cu addition rates.