Alleviation of aluminum phytotoxicity by canola straw biochars varied with their cultivating soils through an investigation of wheat seedling root elongation

• Published in: Chemosphere (Oxford) 2019-03, Vol.218, p.907-914
• Main Authors: Dong, Ying, Wang, Hui, Chang, E, Zhao, Zhenjie, Wang, Ruhai, Xu, Renkou, Jiang, Jun
• Format: Article
• Language: English
• Subjects: Al(III) phytotoxicity alleviation; Base cations; Canola straw biochar; Regional difference; Wheat seedling root elongation
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2018.11.176

The types and amounts of cations and their uptake by plants vary with cultivating soils, which correlates with the carbonates and subsequent alkalis contents in the derived biochars. However, regional differences in the alkaline properties of crop straw biochars are unclear. In the present study, biochars pyrolyzed from canola straws collected from four different regions were used to assess the differences in the alkaline properties among them. The biochars were referred to as YTBC, XCBC, NJBC, and HYBC, respectively, and their feedstocks were collected from four different regions from south to north of China. The NH4OAC exchangeable base cations (K+, Na+, Ca2+, Mg2+) in the biochars were 270.74, 1427.05, 2089.23, and 1516.48 mmol kg−1 for YTBC, XCBC, NJBC, and HYBC, respectively, which were roughly consistent with the exchangeable base cations in the corresponding planting soils (17.57, 28.20, 151.26 and 444.65 mmol kg−1, respectively). The pH, carbonates content, and alkalinity of biochars considerably increased as follows: YTBC  YTBC, which was corroborated by the subsequent findings of Evans blue staining, the remnant aluminum (Al(III)) in the reaction solution and Al(III) distribution in the wheat seedling roots. Thus, planting soil had a dominant influence in alleviating Al(III) phytotoxicity, and studies on crop straw biochar properties concerning alkalinities or liming potentials should not only consider crop genera and pyrolysis conditions, but also cultivating conditions. [Display omitted] •Canola straw biochars properties varied with their cultivating soils.•Aluminum phytotoxicity alleviation varied with biochars biomass and cultivating regions.•Aluminum phytotoxicity alleviation was mainly attributed to biochars liming potential.