Department of Chemistry "Giacomo Ciamician" and C.I.R.I. MAM Tecnopolo di Rimini, University of Bologna, Via Dario Campana 71, 47192 Rimini, Italy.
Department of Chemistry "Giacomo Ciamician", University of Bologna, Campus di Ravenna, via Sant'Alberto 163, 48123 Ravenna, Italy.
Sci Total Environ. 2022 Mar 15;812:151422. doi: 10.1016/j.scitotenv.2021.151422. Epub 2021 Nov 4.
Dissolved organic matter (DOM) is an important organic matter fraction that plays a key role in many biological and chemical processes in soil. The effect of biochar addition on the content and composition of soil organic matter (SOM) and DOM in an agricultural soil in Italy was investigated within a two-year period. UV-Vis spectroscopy and analytical pyrolysis have been applied to study complex components in DOM soil samples. Additionally, analytical pyrolysis was used to provide qualitative information of SOM at molecular level and the properties of biochar before and one year after amendment. A method was developed to quantify biochar levels by thermogravimetric analysis that enabled to identify deviations from the amendment rate. The water-soluble organic carbon (WSOC) concentrations in the amended soils were significantly lower than those in the control soils, indicating that biochar decreased the leaching of DOM. DOM in treated soils was characterized by a higher aromatic character according to analytical pyrolysis and UV-Vis spectroscopy. Moreover, a relatively high abundance of compounds with N was observed in pyrolysates of treated soils, suggesting that biochar increased the proportion of microbial DOM. The results from thermal and spectroscopy techniques are consistent in highlighting significant changes in DOM levels and composition due to biochar application with important effects on soil carbon storage and cycling.
溶解有机物质（DOM）是一种重要的有机物质，在土壤中的许多生物和化学过程中起着关键作用。本研究在为期两年的时间内，调查了生物炭添加对意大利农业土壤中有机质（SOM）和 DOM 含量和组成的影响。利用紫外可见光谱和热解分析研究了 DOM 土壤样品中的复杂成分。此外，热解分析用于提供 SOM 在分子水平上的定性信息以及生物炭在添加前后一年的性质。开发了一种通过热重分析定量生物炭水平的方法，该方法能够识别添加率的偏差。添加生物炭的土壤中的水溶性有机碳（WSOC）浓度明显低于对照土壤，表明生物炭减少了 DOM 的淋溶。根据热解分析和紫外可见光谱，处理土壤中的 DOM 具有更高的芳香特征。此外，处理土壤的热解产物中还观察到相对丰富的含 N 化合物，这表明生物炭增加了微生物 DOM 的比例。热和光谱技术的结果一致，突出了由于生物炭应用导致的 DOM 水平和组成的显著变化，这对土壤碳储存和循环有重要影响。
