PDF(Pubmed)
Abstract：
Cadmium (Cd) contamination in the soil potentially hampers microbial biomass and adversely affects their services such as decomposition and mineralization of organic matter. It can reduce nitrogen (N) metabolism and consequently affect plant growth and physiology. Further, Cd accumulation in plants can pose health risks through vegetable consumption. Here, we investigated consequences of Cd contamination on fertilizer value and associated health risks following the application of biogas residues (BGR) to various soil types. Our results indicate that the application of BGR to all soil types significantly increased dry matter (DM) yield and N uptake. However, the Cd contamination negatively affected DM yield and N recovery from BGR in a dose-dependent manner. Organic N mineralization from BGR also decreased in Cd-contaminated soils. The highest DM yield and N recovery were recorded in sandy soil, whereas the lowest values were observed in clay soil. Cadmium was accumulated in spinach, and health risk index (HRI) associated with its dietary intake revealed that consuming spinach grown in Cd-contaminated soil, with or without BGR, is unsafe. Among the soil types, values of daily intake of metals (DIM) and HRI were lowest in clay soil and highest in sandy soil. However, the application of BGR curtailed HRI across all soil types. Notably, the application of BGR alone resulted in HRI values < 1, which are under the safe limit. We conclude that soil contamination with Cd reduces fertilizer value and entails implications for human health. However, the application of BGR to the soil can decrease Cd effects.
摘要：
土壤中的镉（Cd）污染可能会阻碍微生物生物量，并对其服务产生不利影响，例如有机物的分解和矿化。它可以减少氮（N）代谢，从而影响植物的生长和生理。Further,植物中的Cd积累会通过食用蔬菜对健康构成风险。这里,我们调查了将沼气残留物（BGR）应用于各种土壤类型后，Cd污染对肥料价值和相关健康风险的影响。我们的结果表明，将BGR应用于所有土壤类型均显着提高了干物质（DM）产量和氮素吸收。然而,Cd污染以剂量依赖性方式对DM产量和BGR中的N回收产生负面影响。Cd污染土壤中BGR的有机氮矿化也减少。在沙质土壤中记录到最高的DM产量和氮回收率，而在粘土中观察到最低值。镉在菠菜中积累，与饮食摄入相关的健康风险指数（HRI）表明，食用在Cd污染土壤中生长的菠菜，有或没有BGR，是不安全的。在土壤类型中，金属的每日摄入量（DIM）和HRI值在粘土土壤中最低，在沙质土壤中最高。然而,BGR的应用减少了所有土壤类型的HRI。值得注意的是,单独应用BGR导致HRI值<1,其在安全限度内。我们得出的结论是，Cd污染的土壤会降低肥料价值，并对人类健康产生影响。然而,在土壤中施用BGR可以减少Cd的影响。
