Microbial community response to corn-straw biochar amendment in the rhizosphere of ryegrass grown on ionic rare earth tailings soil

This study investigated how adding corn-straw biochar helps ryegrass grow in degraded ionic rare earth tailings soil by changing the soil microbial community. Ionic rare earth tailings are highly acidic, have poor structure, and lack nutrients, making them very hard to restore. We tested whether biochar helps plants by directly improving soil conditions and by changing the types of microbes living in the soil.We grew ryegrass (Lolium perenne) in pots containing tailings soil mixed with different amounts of corn-straw biochar: 0% (control), 1%, 3%, and 5% by weight. After three months, we measured plant growth and soil properties like pH, available nitrogen/phosphorus/potassium, and organic matter. We used Illumina MiSeq sequencing to analyze the bacterial (16S rRNA gene) and fungal (ITS region) communities in the soil around the roots.The main results were: 1) Biochar, especially at 3% and 5%, greatly increased soil pH, nutrient levels, and organic matter, which improved ryegrass growth. 2) Biochar changed the microbial community, increasing helpful bacteria that solubilize phosphorus (like Sphingomonas and Arthrobacter) and decreasing harmful plant pathogens (like Ralstonia). 3) Analysis of fungal functions showed biochar greatly reduced the number of saprotrophic fungi and plant pathogens. Statistical analysis confirmed that changes in soil pH and available nutrients were the main drivers of these microbial shifts.This dataset contains the raw sequencing files (paired-end reads for 16S and ITS) from 12 soil samples, which include four different biochar treatments with three replicate pots each. These data help explain how biochar works to clean up ionic rare earth tailings soil by improving both the soil environment and its microbial life.