Key Laboratory of Terrestrial Ecological Process, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
Chemosphere. 2011 Jan;82(2):215-22. doi: 10.1016/j.chemosphere.2010.10.018. Epub 2010 Oct 30.
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 CuSO⁴) 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 (< 20mg kg⁻¹) even at higher Cu addition rates.
用牲畜粪便（LM）给农作物施肥是一种常见的废物处理方法，但重复施用含有高浓度重金属（如 Cu）的 LM 可能导致作物毒性和环境风险。为了研究富 Cu 的 LM 对受 Mollisol 影响的小麦的 Cu 有效性和吸收，进行了盆栽实验。LM（最初含 376mgkg⁻¹ Cu）中添加了不同浓度的 Cu（0、100、200、400、600 和 800mgkg⁻¹ 土壤，添加形式为 CuSO₄），以模拟 LM 施用以致土壤 Cu 污染。结果表明，Cu 主要分布在有机结合态，而可还原态的增加最为明显。酸提取态在控制 Cu 的迁移性和生物有效性方面比其他形态更为重要。DTPA 提取态 Cu 可能会高估 Cu 的生物有效性，因为 DTPA 溶液可以提取可溶性和部分稳定的形态。LM 以 1%的水平应用会显著降低 Cu 的迁移性，但以 3%的水平应用则会产生相反的效果。尽管与土壤积累相比，小麦中 Cu 的数量非常低，但根部的 Cu 浓度从 12 增加到 533mgkg⁻¹，而地上部分的 Cu 浓度在 12.1 到 32.7mgkg⁻¹之间变化不大，这表明根部对 Cu 毒性更为敏感。即使在更高的 Cu 添加率下，3%的粪肥应用后谷物中的 Cu 浓度也没有接近 Cu 毒性的阈值（<20mgkg⁻¹）。
