Agronomy Department, Federal University of Sergipe, São Cristóvão, SE, 49100-000, Brazil.
North Florida Research and Education Center, University of Florida, Quincy, 32351, United States.
Chemosphere. 2018 Jun;201:278-285. doi: 10.1016/j.chemosphere.2018.03.038. Epub 2018 Mar 5.
Copper contamination and toxicity in soils is a worldwide problem, especially in areas where copper-based fungicides are applied. Indian mustard (Brassica juncea L.) plants are used in phytoremediation and are also edible crops commonly cultivated in organic agricultural areas. Application of biochar to Cu contaminated soils may reduce Cu availability and uptake, thereby allowing for greater Indian mustard production. A (3 × 2) + 1) experiment in a randomized complete block design was used to evaluate the effect of three different biochars (coconut shell, orange bagasse and sewage sludge) and two application rates (30 and 60 t ha) on Cu uptake by Indian mustard during three successive growth cycles and Cu immobilization in soil, under greenhouse conditions. Coconut husk biochar did not influence available soil Cu; however, its presence increased shoot Cu uptake by 117% and 38% in the two last growth cycles. Orange bagasse biochar, at the 60 t ha application rate, reduced Cu availability, but it was not effective in reducing Cu uptake. Sewage sludge biochar did not affect Cu availability and caused an approximated 100% increase in shoot Cu uptake at the highest application rate. Therefore, the orange bagasse biochar is the most effective whereas the sewage sludge biochar is the least in Cu immobilization. None of the biochars was shown to be suitable as soil amendment to reduce the uptake of Cu by Indian mustard. However, coconut shell and sewage sludge biochar can be effectively applied to soil as an auxiliary tool to remediate Cu-contaminated soils.
土壤中的铜污染和毒性是一个全球性问题，特别是在使用铜基杀菌剂的地区。芥菜（ Brassica juncea L. ）植物被用于植物修复，也是有机农业地区常见的可食用作物。生物炭施用于 Cu 污染土壤可降低 Cu 的有效性和吸收，从而允许更大规模地种植芥菜。采用随机完全区组设计的（3×2）+1 实验，评估了三种不同生物炭（椰子壳、橙渣和污水污泥）和两种施用量（30 和 60 t ha）对 Cu 污染土壤中芥菜在三个连续生长周期中的吸收和 Cu 固定的影响，在温室条件下进行。椰子壳生物炭对土壤有效 Cu 没有影响；然而，其存在使最后两个生长周期中地上部 Cu 吸收增加了 117%和 38%。橙渣生物炭在 60 t ha 的施用量下降低了 Cu 的有效性，但在降低 Cu 吸收方面效果不佳。污水污泥生物炭不影响 Cu 的有效性，在最高施用量下使地上部 Cu 吸收增加了约 100%。因此，橙渣生物炭的固定 Cu 效果最显著，而污水污泥生物炭的固定 Cu 效果最不显著。没有一种生物炭被证明适合作为土壤改良剂来减少芥菜对 Cu 的吸收。然而，椰子壳和污水污泥生物炭可以有效地作为一种辅助工具应用于土壤中，以修复 Cu 污染土壤。
