The effect of biochar on soil-plant-earthworm-bacteria system in metal(loid) contaminated soil

Abstract Increasing biochar is applied to the metal(loid) contaminated soil. However, effects of biochar on the soil-plant-earthworm-bacteria ecosystem, especially on the gut microbes of soil animals, remain largely unknown and require further research. Here, sewage sludge biochar (SSBC) and rice straw biochar (RSBC) were used in metal(loid) contaminated soils to investigate the available metal(loid) change in soils and the impact on the metal(loid) bioaccumulation in the plant and earthworm. Moreover, effects of biochar amendments on the gut bacteria of earthworms were determined by using high throughput sequencing. Our results showed that RSBC amendments had a significant suppression on the availability of cadmium, but significantly increased arsenic availability in soils (P