Response and mechanisms of Amorphophallus konjac agronomic traits and disease occurrence after biochar application

Abstract

Amorphophallus konjac is widely used in fields such as food science, nutrition, health care, and light industry because of its rich glucomannan content. However, low yields and widespread disease remain prominent problems that need to be addressed. In this study, ‘Jindi No.1′ Amorphophallus konjac was used as the experimental material. Effects of bamboo charcoal biomass addition and particle size were investigated on agronomic traits, disease occurrence of A. konjac, soil physicochemical properties, and microbial response to biochar application. The results revealed that biochar application significantly affected agronomic traits, yield, and disease occurrence of A. konjac. The plant height and petiole length of A. konjac increased by 28.88 % and 36.21 %, respectively, compared with the control group after treatment with 5 % biochar and 300 mesh particle size. The weights of the second-generation corm and individual plants increased by 43.12 % and 60.09 %, respectively, compared with the control group. Additionally, the disease incidence and index decreased by 23.81 % and 46.43 %, respectively. Furthermore, biochar application significantly affected the physical and chemical properties of the soil, leading to improvements in various physical and chemical indicators. Among the treatment groups, the most significant changes were observed in the treatment groups with a particle size of 300 mesh and an addition of 4 % and 5 % biochar. Moreover, the addition of biochar and its particle size significantly increased the relative abundance of Ascomycota, Mortierellomycota, and other groups, but significantly reduced the relative abundance of Basidiomycota. At the genus level, 26 different genera were identified, including Mortierella, Melanospora, and Phaalemonium. Therefore, biochar-mediated changes in the soil physicochemical properties and microbial community structure, lead to improvements in agronomic traits, increased yields, and reduced disease occurrence in A. konjac.