Details

Autor(en) / Beteiligte

• Yu, Weijia
• Ren, Tusheng
• Duan, Yinghua
• Huai, Shengchang
• Zhang, Qingyue
• Cai, Zejiang
• Lu, Changai

Titel

Mechanism of Al toxicity alleviation in acidic red soil by rice-straw hydrochar application and comparison with pyrochar

Ist Teil von

• The Science of the total environment, 2023-06, Vol.877, p.162849-162849, Article 162849

Ort / Verlag

Netherlands: Elsevier B.V

Erscheinungsjahr

2023

Quelle

Elsevier ScienceDirect Journals

Beschreibungen/Notizen

• In the past decade, biochar has been widely regarded as a new type of soil conditioner that can effectively control soil acidification and alleviate Al toxicity. Hydrochar is identified as a more economical carbon material than pyrochar, but its effect on Al toxicity and the associated mechanism have not been studied. Thus, a two-stage indoor incubation experiment was conducted to investigate the effect of rice-straw hydrochar (HC, application rate: 1/2/3 %) on maize seedling root growth, soil solution Al activity, soil exchangeable Al and pH buffering ability in acidic red soils from two sites. We also used pyrochar (PC, application rate: 3 %) produced from the same rice straw for comparison. Except for HC-1 %, both hydrochar and pyrochar addition significantly stimulated relative root elongation (136.36 % ~ 284.09 %), diminished the cell death ratio (27.96 % ~ 85.56 %) and Al content in root tips (18.80 % ~ 80.11 %) by decreasing the total Al content (44.78 % ~ 76.10 %) and the proportion of Al3+ species (27 % ~ 32 %) in soil solution. Hydrochar did not significantly promote the soil pH buffer capacity (pH-BC) or effective cation exchange capacity (ECEC), while PC-3 % did. The DOC (dissolved organic carbon) content of soil solution was dramatically elevated by 203.9 % ~ 783.2 % after hydrochar addition. Hydrochar mitigates Al activity in soil solution mainly through Al-DOC complexation and adsorption, thus suppressing the Al toxicity of maize roots. Hydrochar may be an economical soil amendment for ameliorating Al toxicity despite its overall alleviation effect on Al toxicity being lower than pyrochar. [Display omitted] •Rice-straw hydrochar alleviated the Al phytotoxicity to maize root.•Rice-straw hydrochar reduced the total Al content in soil solution by its excellent Al adsorption characteristics.•The addition of rice-straw hydrochar altered the distribution of Al species in soil solution mainly by Al-DOC complexation.•Mechanism of Al toxicity mitigation differs between hydrochar and pyrochar because of components and structure differences.