Abstract

Biochar-derived dissolved organic matter (BDOM) plays key roles in soil ecosystem by affecting soil physicochemical and biological properties and supplying nutrients to soil microbes. It can either enhance or suppress the growth of certain soil microorganisms, depending on its composition and content of labile organic compounds. This review aims to discuss and summarize the role of BDOM in modifying soil microbial functioning, microbial community structure, and enzymatic activity. We mainly focus on the role of BDOM as a function of its concentration, type of feedstock biomass, and pyrolysis temperature (PT). Results show that saw dust- and manure-based biochars produce higher BDOM concentrations than straw-, bone-, and sludge-based biochars. The types of feedstock biomass and its PT determine BDOM characteristics and its interaction with soil microbial communities. Plant-derived biochar with pyrolysis temperature ≤300 °C often results in a more aliphatic BDOM than that with pyrolysis temperature ≥500 °C, which yields a more aromatic BDOM. BDOM of plant biochar contains higher specific ultraviolet absorbance (SUVA) and humification index (HIX) than that of manure biochar. The SUVA and HIX of BDOM positively correlate (R²=0.68–0.96) with the content of total fatty acid methyl esters, but negatively correlate with the abundances of actinomycetes, arbuscular mycorrhizae, and fungal communities. However, the environmental fate of BDOM in biochar amended soil requires long-term experiment, both in laboratory and field scales, to provide a full understating of BDOM interaction with soil organic matter and microorganisms and help to tailor a safe utilization of biochar in agroecosystems.

摘要

生物炭衍生的溶解有机物 (BDOM) 通过影响土壤理化和生物学特性以及为土壤微生物提供养分，在土壤生态系统中发挥着关键作用。它可以增强或抑制某些土壤微生物的生长，这取决于它的组成和不稳定有机化合物的含量。本综述旨在讨论和总结 BDOM 在改变土壤微生物功能、微生物群落结构和酶活性方面的作用。我们主要关注 BDOM 的作用与其浓度、原料生物量类型和热解温度 (PT) 的函数关系。结果表明，基于锯末和粪便的生物炭产生的 BDOM 浓度高于基于秸秆、骨头和污泥的生物炭。原料生物量的类型及其 PT 决定了 BDOM 的特征及其与土壤微生物群落的相互作用。与热解温度≥500 °C 相比，热解温度≤300 °C 的植物来源的生物炭通常会产生更多的脂肪族 BDOM，从而产生更芳香的 BDOM。植物生物炭的 BDOM 比粪便生物炭含有更高的特定紫外线吸光度 (SUVA) 和腐殖化指数 (HIX)。BDOM的SUVA和HIX呈正相关（R ² =0.68–0.96)与总脂肪酸甲酯含量有关，但与放线菌、丛枝菌根和真菌群落丰度呈负相关。然而，BDOM 在生物炭改良土壤中的环境归宿需要在实验室和田间规模进行长期实验，以全面了解 BDOM 与土壤有机质和微生物的相互作用，并帮助定制生物炭在农业生态系统中的安全利用。