Biochar amendments improve soil functionalities, microbial community and reduce Pokkah boeng disease of sugarcane

Abstract

Abstract Background Biochar is mainly used to enhance soil fertility, microbial activity, improve plant performance and reduce disease incidence. Methods A greenhouse experiment was designed to investigate the response of biochar on rhizosphere soil chemical properties, enzyme activity, microbial communities, and sugarcane Pokkah boeng disease (PB). Two sugarcane varieties Zhongzhe 9 (Z9) and ROC22, susceptible/resistant to PB, were cultivated and treated with: no biochar, 15 t ha−1 biochar, and 30 t ha−1 biochar. Results The amendment of 30 t ha−1 of biochar (B2) significantly improve soil pH by 1.50% and 9.61% compared with that of B1 and B0, followed by 0.51% increase by 15 t ha−1 of biochar (B1) compared with that of control (B0). The application of 15 t ha−1 biochar significantly increased available phosphorus (AP) and ammonium nitrogen (NH4+–N) by 209.93 mg kg−1 and 12.1 mg kg−1, while the application of 30 t ha−1 of biochar significantly increased 241.04 mg kg−1 of available potassium (AK) (P < 0.05). Furthermore, biochar application increased the activities of soil acid phosphatase (S-ACP), urease (S-UE), and sucrase (S-SC). Alpha diversity analysis showed that the addition of biochar significantly altered the variety and abundance of rhizosphere microorganisms (P < 0.01) and increased the relative abundance of beneficial microorganisms Rhodanobacteraceae, Stachybotryaceae, Agaricacea, Talaromyces, Nectriaceae, Sistotrema, and Bacillus (P < 0.01). There was a significant decrease in the relative abundance of the soil pathogen Fusarium (P < 0.01). Conclusion These findings suggested that the application of 15 t ha−1 biochar could bring desirable variations in soil functionalities, modulate soil microbial community by increasing soil health and reduce the disease index of PB. Graphical Abstract