Cation exchange capacity and composition of soluble soil organic matter fractions
Cation exchange capacity and composition of soluble soil organic matter fractions
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DOI：
10.2136/sssaj2007.0340
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发表时间：
2008-09-01
影响因子：
2.9
通讯作者：
Gerke, H. H.
中科院分区：
文献类型：
--
作者：
Kaiser, M.;Ellerbrock, R. H.;Gerke, H. H.
土壤阳离子交换量（CEC）不仅取决于粘土矿物的数量和组成，而且还取决于土壤有机质（SOM）的数量和组成。虽然土壤粘土矿物的CEC已被深入研究，但对有机质（OM）组分的CEC知之甚少，特别是那些用新开发的SOM提取技术获得的组分。本研究的目的是开发和休息的方法，以定量测定提取的有机质馏分的CEC和CEC（OM）的有机质官能团可能负责阳离子的吸附。水和焦磷酸盐可溶性有机质组分依次从两个著名的长期田间试验不同管理的耕地土壤中提取。通过应用标准渗滤法测定与石英砂（4.97 g）混合的冻干焦磷酸盐可溶性OM级分[OM（PY）]（0.03 g）的CEC。采用傅里叶变换红外光谱（FTIR）分析了OM（PY）的化学组成。对于A地块，除了那些施肥与农家肥，OM（PY）馏分的吸附性能被发现是特定的网站，并反映土壤和作物轮作的影响。有机质阳离子交换量（PY）占土壤阳离子交换量的相对贡献率（0.8-11.6%）取决于土壤碳含量和可提取性。然而，对于所有图，发现用FTIR光谱测定的OM（PY）中的羧基官能团的相对含量与OM（PY）的CEC线性相关，与纯有机物质相似。这种关系表明CEC测定OM（PY）馏分的有用性。结果表明，有机质中羧基官能团的相对含量（PY）反映了施肥和轮作对有机质吸附特性的长期影响。
The cation exchange capacity, (CEC) of soils depends on the amount and composition not only, of clay minerals but also of soil organic matter (SOM). While the CEC of soil clay minerals; has been intensively studied, little is known about the CEC of organic matter (OM) fractions, in particular those obtained with newly developed SOM extraction techniques. The objective of this study was to develop and rest a method to quantitatively determine the CEC of extracted OM fractions and to relate CEC(OM) to OM functional groups Possibly responsible for sorption of cations. Water- and pyrophosphate-soluble OM fractions were sequentially extracted from differently managed arable soils of two well-known long-term field experiments. The CEC of a freeze-dried pyrophosphate-soluble OM fraction [OM(PY)] (0.03 g) mixed with quartz sand (4.97 g) was determined by applying the standard percolation method. The chemical composition of OM(PY) was analyzed by Fourier-transform infrared (FTIR) spectroscopy. For A plots except those fertilized with farmyard manure, the sorption properties of the OM(PY) fraction were found to be site specific and to reflect soil and crop rotation effects. The relative contribution of the CEC of OM (PY) to the CEC of the soil (0.8-11.6%) is dependent on soil C content and extractability. For all Plots, however, the relative contents of carboxylic functional groups in OM(PY) determined with FTIR spectroscopy was found to be linearly related to the CEC of the OM(PY), similar to pure organic substances. This relationship indicates the usefulness of CEC determination on OM(PY) fractions. The results suggest that the relative contents of carboxylic functional groups in OM(PY) reflect long-term effects of fertilization and crop rotation on the sorption properties of the SOM.