Effects of Arbuscular Mycorrhizal Fungi (AMF) and Biochar On the Growth of Pepper (Capsicum annum L.) Under Salt Stress

Soil salinity is a significant abiotic factor that negatively affects the growth and yield of many plants. Separately, biochar and arbuscular mycorrhizal fungus contributed positively to salt-stressed plant growth. To alleviate salinity stress and promote pepper growth, biochar and mycorrhiza are rarely researched together. In this work, the effects of salt stress (AMF) and biochar (BC) applications on the pepper (Capsicum annum L.) plant's morphological and physiological growth characteristics and some soil properties were investigated. Biochar (2% and 4%) and AMF inoculum (Funneliformis mosseae (Fm) and ERS commercial AMF inoculum) were applied to a commercial pepper cultivar (Sera Demre 8) at varying salt concentrations (0 mM, 50 mM, 100 mM, and 150 mM) in order to determine the optimal treatments (AMF inoculum and biochar concentration). In general, when the salt concentration increased, the morphological growth values of the pepper plant and the AMF density decreased, but the EC value of the soil increased. In general, the plants were able to endure a salt concentration of 100 mM, but their sensitivity increased when exposed to 150 mM NaCl. Biochar and AMF independently increased plant growth parameters, leaf relative water content (LRWC), and phosphorus (P), while decreasing membrane injury index (MII) values. The interaction biochar and AMF positively improved microbial activity under conditions of salt stress, while mycorrhizal dependency did not arise in AMF treatments. Based on the results, it was found that the 2% biochar ratio and F. mosseae were beneficial to the morphological development and growth of AMF. Therefore, it was determined that the synergistic effect of AMF and biochar might be used as a viable and sustainable agricultural alternative to prevent salt stress damage in pepper growing.

Automated summary

Soil salinity negatively affects plant growth and yield, but biochar and arbuscular mycorrhizal fungus (AMF) can positively contribute to salt-stressed plant growth. This study investigated the effects of salt stress, AMF, and biochar applications on pepper plants, and found that increasing salt concentration decreased plant growth and AMF density while increasing soil electrical conductivity. Additionally, both biochar and AMF increased plant growth parameters and decreased membrane injury index values. The interaction between biochar and AMF improved microbial activity under salt stress conditions. Overall, using AMF and biochar together can potentially prevent salt stress damage in pepper growing.