A comparison of extraction procedures for water-extractable organic matter in soils
A comparison of extraction procedures for water-extractable organic matter in soils
复制标题
DOI：
10.1111/ejss.12156
复制
发表时间：
2014-07-01
影响因子：
4.2
通讯作者：
Lucas, Y.
中科院分区：
文献类型：
--
作者：
Guigue, J.;Mathieu, O.;Lucas, Y.
土壤中溶解性有机质（DOM）的特性通常通过室内实验来确定。可以使用许多不同的方案来从土壤中提取有机物质。本研究以5种风干土壤为材料，比较了3种水溶性有机质（WEOM）的提取方法：（i）高温高压渗滤法（PH-WEOC），（ii）水溶性有机碳（WEOC），（iii）振荡1h，（iv）水溶性有机碳（WEOC），（v）水溶性有机碳（WEOC）。和（iii）土壤可提取有机碳（LEOC），在环境条件下土壤柱的沥滤。我们量化了有机碳的提取率; WEOM的质量通过UV吸光度、潜在生物降解性（48天孵育）和荧光激发发射矩阵（FEEM）的平行因子分析（PARAFAC）建模来表征。溶解性有机碳（DOC）的生物降解过程可以用两个有机碳库来描述。不稳定和稳定的DOC池的比例之间的WEOC和LEOC方法只有轻微的差异，而PH-WEOC包含更稳定的DOC。三种方法测定的不稳定和稳定DOC库的矿化速率常数相似。FEEM被分解成三个组成部分：两个腐殖类荧光团和一个类荧光团。提取方法的效果是差的判别和最相似的程序是PH-WEOC和LEOC，而WEOC提取物中的类胡敏素荧光团耗尽。这项研究表明，WEOM质量主要取决于土壤特性，提取方法对WEOM质量的影响较小，但仍然很大。此外，我们观察到相当大的提取程序和土壤类型之间的相互作用，表明方法引起的差异WEOM质量随土壤特性而变化。
The characteristics of dissolved organic matter (DOM) in soils are often determined through laboratory experiments. Many different protocols can be used to extract organic matter from soil. In this study, we used five air-dried soils to compare three extraction methods for water-extractable organic matter (WEOM) as follows: (i) pressurised hot-water-extractable organic carbon (PH-WEOC), a percolation at high pressure and temperature; (ii) water-extractable organic carbon (WEOC), a 1-hour end-over shaking; and (iii) leaching-extractable organic carbon (LEOC), a leaching of soil columns at ambient conditions. We quantified the extraction yield of organic carbon; the quality of WEOM was characterized by UV absorbance, potential biodegradability (48-day incubation) and parallel factor analysis (PARAFAC) modelling of fluorescence excitation emission matrices (FEEMs). Biodegradation of dissolved organic carbon (DOC) was described by two pools of organic C. The proportions of labile and stable DOC pools differed only slightly between the WEOC and LEOC methods, while PH-WEOC contains more stable DOC. The mineralization rate constants of both labile and stable DOC pools were similar for the three methods. The FEEMs were decomposed into three components: two humic-like fluorophores and a tryptophan-like fluorophore. The effect of extraction method was poorly discriminant and the most similar procedures were PH-WEOC and LEOC while WEOC extracts were depleted in humic-like fluorophores. This study demonstrates that WEOM quality is primarily determined by soil characteristics and that the extraction method has a smaller, but still significant, impact on WEOM quality. Furthermore, we observed considerable interaction between extraction procedure and soil type, showing that method-induced differences in WEOM quality vary with soil characteristics.