Soil Organic Matter : Its Fractionation and Role in Soil Structure
Soil Organic Matter : Its Fractionation and Role in Soil Structure
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发表时间：
2010
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通讯作者：
A. Whitbread
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作者：
A. Whitbread
了解土壤中SOM的形态和功能对作物的可持续生产至关重要。SOM分选的各种方法被用来研究SOM的形态，并获得SOM与聚合体形成之间的相互作用的理解。物理SOM分馏技术是基于SOM与不同大小的颗粒相关联的概念。结构和功能不同。SOM的这种分布是通过破坏土壤结构来研究的，通常是通过超声波和震动，然后根据大小或密度分离物理组分。与使用这些技术有关的问题包括：SOM重新分布成通常不存在的大小分离体，不完全分散，宏观om的破碎，以及任意的大小和密度限制。物理SOM分选技术在研究SOM的结构和功能方面是有用的，但在识别负责维护土壤结构的有机结合剂方面的应用是有限的。大多数土壤依靠颗粒的聚集来维持土壤微生物和动物活动以及植物生长的有利条件。SOM的某些组分如多糖、土壤腐殖质、根系物质和真菌菌丝等对土壤结构稳定具有重要作用。用高锰酸钾氧化法测定挥发性碳和总碳，发现水稳定团聚体中存在碳的浓度。碳含量越高，大团聚体的稳定性越高，这可能是由于有机键合机制。管理对土壤有机质的影响，特别是对这些不稳定成分的影响，以及土壤结构的变化对可持续农业系统的发展至关重要
An understanding of the form and function of SOM in soil is essential to sustainable crop production. Various methods of SOM fractionation are used to study SOM forms and to gain an understanding of interaction between SOM and aggregate formation. Physical SOM fractionation techniques are based on the concept that SOM associated with particles of various sizes. differs in structure and function. This distribution of SOM has been studied by disrupting soil structure, commonly by sonication and shaking, followed by the separation of physical fractions on the basis of size or density. Problems associated with the use of these techniques include the redistribution of SOM into size separates in which it is not normally located, incomplete dispersion, fragmentation of macro-OM, and arbitrary size and density limits. Physical SOM fractionation techniques have been useful in studying SOM structure and function, but their use for identifying organic binding agents, responsible for maintenance of soil structure, is limited. Most soils rely on aggregation of particles to maintain favourable conditions for soil microbial and faunal activity and plant growth. Certain components of SOM such as polysacchaJides, soil humic substances, root material and fungal hyphae have an important role in soil structural stabilisation. The measurement of labile carbon by oxidation with potassium permanganate and total carbon has shown a concentration of carbon in water stable aggregates. The stability of macroaggregates increased at higher levels of carbon, presumably due to organic bonding mechanisms. The effect of management upon SOM, specifically upon these labile components, and changes in soil structure are essential for the development of sustainable agricultural sys-