Impact of rice-husk biochar on soil attributes, microbiome interaction and functional traits of radish plants: A smart candidate for soil engineering

This study is based on the application of different doses of rice husk biochar; RHB (1, 5, 10, 15, and 20 t/ha) in wastewater-irrigated soil to observe its impact on the soil qualities and functional attributes of the radish plants. The results showed that the RHB treatments increased the soil pH, electrical conductivity (EC), bulk density (BD), soil organic carbon (SOC), total nitrogen (TN), available phosphorous (AP), enzymatic activities, and microbial biomass in the soil. The soil metagenome analysis at 15 t/ha showed more abundance of microbial communities like Actinobacteria, Acidobacteria, and Nitrospira over to control soil. On the other hand, more significantly it led to a reduction in the availability of Cd, Cr, Ni, Zn, and Cu by 73, 60, 63, 61, and 68%, respectively maximally at 20 t/ha dose of biochar application. Along with that it also led to the level of the all the toxic heavy metals below their safe limit in the edible part of the radish plants. All the doses of RHB application have resulted improvements in functional attributes of the radish plants by reducing the production of oxidative biomarkers more significantly at 15 and 20 t/ha doses of biochar compared to the control plants. Among all the doses the biomass of edible parts of plant i.e., root was increased and the maximum increment was found at 15 t/ha over to control plants and later on, there was an insignificant difference. The total concentrations of Cd, Cr, Ni, Zn, and Cu were decreased in the root and shoot of the plants in a dose-dependent manner. The correlation biplot also showed that with the amendment of biochar, there was a significant correlation between the soil properties and plant yield.