Two-year study of biochar: Achieving excellent capability of potassium supply via alter clay mineral composition and potassium-dissolving bacteria activity

• Published in: The Science of the total environment Vol. 717; p. 137286
• Main Authors: Zhang, Mengyang, Riaz, Muhammad, Liu, Bo, Xia, Hao, El-desouki, Zeinab, Jiang, Cuncang
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.05.2020
• Subjects: acid soils; Bacteria; bacterial communities; Bacterial community; Biochar; cation exchange capacity; Charcoal; Clay; Clay minerals; environmental factors; mineral content; Minerals; organic matter; pathogens; peanut hulls; phosphorus; pollutants; Potassium; potassium fertilizers; Potassium-dissolving bacteria; pyrolysis; Soil; soil bacteria; Sphingomonas; Clay minerals; Potassium-dissolving bacteria; Biochar; Potassium; Bacterial community
• ISSN: 0048-9697; 1879-1026; 1879-1026
• DOI: 10.1016/j.scitotenv.2020.137286

At present, there has been renewed interest in biochar research, but most of them were focused on the short-term effects of biochar and the information of long-term application of biochar is still lacking. In addition, the nutrient mechanism of biochar has rarely been the subject of research. This research explored the effect of potassium (K) nutrient and the response of bacterial communities to biochar in yellow-brown soil based on two-year experiment. In this study, we used peanut shell biochar obtained by pyrolysis at 400 °C, and at the same time, 0%, 20%, 40%, 100% conventional potassium fertilizer were used. The results indicated that the effective improvement of biochar on acidic soil was long-term and 2% biochar replaced 40% conventional potassium fertilizer. Biochar accelerated the conversion of slowly-available K to available K by changing the composition of clay minerals and promoting the growth of K-dissolving bacteria. From the perspective of bacterial community, biochar significantly increased the relative abundance of Sphingomonas, Gaiella, and Elev-16S-1332, which improved the potential ability of soil to degrade pollutants and inhibit pathogens. The pH, organic matter, cation exchange capacity (CEC), and available phosphorus and potassium were important environmental factors that caused significant effects in the bacterial community of yellow-brown soil. Overall, the study demonstrates that biochar is not only an effective alternative to potash fertilizer but also improves soil bacterial communities. [Display omitted] •This research explored the effect of potassium (K) nutrient and bacterial communities to biochar based on two-year experiment.•2% biochar replaced 40% conventional potassium fertilizer.•Biochar accelerated the conversion of slowly-available K to available K.•Biochar stimulated beneficial changes in bacterial community.