The effects and underlying mechanisms of modified biochar combined with nitrification inhibitors on nitrous oxide mitigation in acidic soils

作者：Churong Liu, Huayi Chen, Bo Li, Qihua Wu, Wenling Zhou, Diwen Chen, Junhua Ao · 发表于：Ecotoxicology and Environmental Safety · 年份：2025 · DOI：10.1016/j.ecoenv.2025.118876 · 被引用次数：4 · 研究领域：Soil Carbon and Nitrogen Dynamics、Clay minerals and soil interactions、Soil and Unsaturated Flow

Acidic soils are recognized as hotspot for nitrous oxide (N 2 O) emissions, and effective N 2 O mitigation strategies are lacking. Biochar and its modified products have emerged as promising soil amendments for improving soil quality and mitigating N 2 O emissions. However, the mitigation efficiency of biochar and modified biochar and whether it can synergize with the nitrification inhibitor (3,4-dimethylpyrazole phosphate; DMPP) to further decrease N 2 O emission in acidic soils has not been sufficiently investigated. Therefore, this study investigated the effects and mechanisms of pristine biochar (B1), alkali-modified biochar (B2), and polyethylenimine-alkali-modified biochar (B3), applied alone or in combination with DMPP on N₂O emissions. The results showed that B2 application significantly decreased N 2 O emission by 38.9 %, achieving higher mitigation efficiency than B1. Nevertheless, B3 application significantly increased N 2 O emissions by 119.5 %. Combining B1 with DMPP did not achieve higher N 2 O mitigation efficiency compared with DMPP alone, likely because B1 amendment observably improved soil organic carbon. Notably, a synergistic effect on N₂O mitigation (59.6 %) was observed when B2 was combined with DMPP. After alkali modification, B2, with the largest specific surface areas, recruited more N 2 O reducing microbes and efficiently increased the nosZ gene abundance. In addition, B2 was prepared through high-temperature carbonization, resulting in lower C conte...