College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian Province, China; Key Research Laboratory of Soil Ecosystem Health and Regulation in Fujian Provincial University, Fuzhou 350002, Fujian Province, China; Department of Soil Science, Joseph Sarwuan Tarka University, P.M.B, 2373 Makurdi, Nigeria.
College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian Province, China; Key Research Laboratory of Soil Ecosystem Health and Regulation in Fujian Provincial University, Fuzhou 350002, Fujian Province, China.
Sci Total Environ. 2022 Mar 20;813:152495. doi: 10.1016/j.scitotenv.2021.152495. Epub 2021 Dec 27.
Agricultural soils contribute a significant amount of anthropogenic CO emission, a greenhouse gas of global environmental concern. Hence, discovering sustainable materials that can capture CO in cultivated soils is paramount. Since the effect of biochar on C mineralization/retention in fertilized soils is unclear, we produced biochar-based MgO and sepiolite-nanocomposites with CO capture potential. The field-scale impacts of the modified-biochars were evaluated on net C exchange rate (NCER) periodically for 3 months in fertilized plots. The effects of the modified-biochar on organic-C mineralization, the activities, and dynamics of C-cycling-related 16S rRNA which are unknown, were investigated. Results revealed an initial rapid and higher cumulative CO emission from the sole fertilizer treatment (F). Unlike the biochar treatment (BF), the successful incorporation of MgO/Mg(OH) nanoparticles into the matrix and surface of biochar, and the potential formation of MgCO with soil CO, mitigated CO emission, especially in the MgO-modified biochar (MgOBF), compared to the sepiolite-biochar treatment (SBF). Compared to F and BF, the higher C retention as MgCO in the modified biochar treatments led to an increase in cellulase activity, stimulation of key C-cycling-related bacteria, and the expression of genes associated with starch, sucrose, amino sugar, nucleotide sugar, ascorbate, aldarate, cellulose, and chitin degradation, thus, increasing organic C mineralization. Among the modified-biochar treatments, higher C mineralization was recorded in SBF, resulting in increased cumulative CO emission, despite its initial capture for up to 42 days. However, MgOBF was effective in capturing soil-derived CO, despite the increased C mineralization compared to biochar. The changes in soil moisture and temperature significantly regulated NCER. Also, the modified biochars positively influenced the distribution of C-cycling-related bacteria by improving soil pH and available nutrients. Among the modified biochars, the observed higher mitigation effect of MgOBF on NCER indicated that it could be preferably applied in agricultural soils.
农业土壤是人为 CO 排放的重要来源，也是全球环境关注的温室气体。因此，发现能够在耕作土壤中捕获 CO 的可持续材料至关重要。由于生物炭对施肥土壤中 C 矿化/保留的影响尚不清楚，我们制备了具有 CO 捕集潜力的基于生物炭的 MgO 和海泡石纳米复合材料。在施肥区，定期评估改性生物炭对净碳交换率（NCER）的田间尺度影响，为期 3 个月。研究了改性生物炭对有机-C 矿化、C 循环相关 16S rRNA 活性和动态的影响，这些影响尚不清楚。结果表明，单独施肥处理（F）的 CO 排放初始迅速且累积量更高。与生物炭处理（BF）不同，MgO/Mg(OH)纳米颗粒成功地掺入生物炭基质和表面，以及与土壤 CO 形成 MgCO，减轻了 CO 排放，尤其是在 MgO 改性生物炭（MgOBF）中，与海泡石-生物炭处理（SBF）相比。与 F 和 BF 相比，改性生物炭处理中更多的 C 以 MgCO 的形式保留导致纤维素酶活性增加，刺激与关键 C 循环相关的细菌，以及与淀粉、蔗糖、氨基糖、核苷酸糖、抗坏血酸、醛酸、纤维素和几丁质降解相关的基因表达增加，从而促进有机-C 矿化。在改性生物炭处理中，尽管在最初的 42 天内捕获了多达 42 天，但 SBF 中记录的 C 矿化更高，导致累积 CO 排放增加。然而，与生物炭相比，MgOBF 能够有效地捕获土壤衍生的 CO。土壤水分和温度的变化显著调节了 NCER。此外，改性生物炭通过改善土壤 pH 值和有效养分，对 C 循环相关细菌的分布产生积极影响。在改性生物炭中，观察到 MgOBF 对 NCER 的缓解效果更高，表明其在农业土壤中可能更优选应用。
