生物质炭及其与土壤腐殖质碳的关系

BIOCHAR AND ITS RELATION TO HUMUS CARBON IN SOIL: A SHORT REVIEW

土壤中生物质炭(Biochar C,BcC)与腐殖质碳(Humus C,HC)之间是否存在发生学联系或转化关系是近年来土壤学和地球化学领域关注的热点和亟待解决的科学问题。BcC是以生物中的活性有机质为原料,在低氧或无氧环境下经高温形成的含碳物质;而腐殖质是死亡的动植物在土壤中经微生物作用而形成的含碳的多聚体化合物。本文回顾了近20年来,特别是近10年来国内外学者对于BcC与HC之间关系的研究进展。已有的研究表明,BcC可经微生物作用而转化为HC,但二者间转化的途径以及二者间物理、化学以及生物学特性比较的研究仍存在不足。本文比较了化学氧化法、分子标志物法、氢热解法、热化学氧化法、紫外光氧化法、核磁共振法在BcC定量分析中的优劣;详细介绍了扫描电镜、元素组成分析、红外光谱、X电光子谱能、热重分析、热解-气质-质谱和核磁共振法在BcC结构表征中的应用。系统论述了对BcC和HC进行结构比较和转化关系探究的可行性。

For the past few years, whether there is any genealogical relationship between biochar C （BcC） and humus carbon （HC） has been a hot spot in both pedology and geochemistry and a scientific issue for urgent solution. BcC is a kind of carbon-contained material,transformed from bioactive organic matter in an environment high in temperature and low in or free of oxygen,while humus is a kind of carbon-contained polymeric compound formed as a product of microorgan- isms decomposing dead plants or animals in soil. This review covered works done by foreign and domestic researchers on the relationship between BcC and HC in the recent 20 years, especially the recent 10 years. The researches available suggested that BcC could be transformed into HC by microorganisms. But the work on paths of the transformation and comparison between BcC and HC in physical,chemical and biological feature is still insufficient. Advantages and disadvantages were analyzed of a variety of methods, such as chemical oxidation, molecule marker analysis, hydropyrolysis,thermo-chemical oxidation, UV-oxidation, and nuclear magnetic resonance （NMR） ,used in quantitative analysis of BcC. Detailed intro- duction was presented to the application of scanning electron microscopy （SEM）, elementary analysis （ EA）, infrared spectroscopy （IR） , X-ray photoelectron spectroscopy （XPS） , thermogravimetric analysis （TGA） , Pyrolysis-Gas chromatogra- phy-Mass spectroscopy（Py-GC-MS） and NMR to structural characterization of BcC. Feasibilities were also elaborated of exploring comparison in structure and transformation between BcC and HC.