SOIL ORGANIC-MATTER AND STRUCTURAL STABILITY - MECHANISMS AND IMPLICATIONS FOR MANAGEMENT
SOIL ORGANIC-MATTER AND STRUCTURAL STABILITY - MECHANISMS AND IMPLICATIONS FOR MANAGEMENT
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DOI：
10.1007/bf02205590
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发表时间：
1984-01-01
期刊：
影响因子：
4.9
通讯作者：
OADES, JM
中科院分区：
文献类型：
--
作者：
OADES, JM
气孔和颗粒的稳定性对植物的最佳生长至关重要。两类聚集体的宏观（bbb250 μm）和微观（<250 μm）依赖于有机质的稳定性，以抵抗快速润湿引起的破坏力。络合有机酸的吸附增加了粘土上的负电荷，促进了粘土颗粒从微团聚体中分散。这些酸是由植物、细菌和真菌产生的。然而，粘土在微聚集体中的分散性被多糖的结合作用所抵消，多糖主要是由细菌产生的粘液，但也被植物根和真菌菌丝所抵消。多价阳离子作为有机胶体和粘土之间的桥梁，也增强了微聚集体的稳定性。大团聚体被活的和分解的植物根系包围，因此对管理很敏感，当草被种植和土壤不受干扰时，它们的数量会增加。缺乏根系生长，即休耕则有相反的效果。讨论了土壤结构管理的各种含义。
The stability of pores and particles is essential for optimum growth of plants. Two categories of aggregates macro- (> 250 μm) and micro- (<250 μm) depend on organic matter for stability against disruptive forces caused by rapid wetting. Dispersion of clay particles from microaggregates is promoted by adsorption of complexing organic acids which increase the negative charge on clays. The acids are produced by plants, bacteria and fungi. However, the dispersibility of clay in microaggregates is offset by the binding action of polysaccharides, mainly mucilages produced by bacteria, but also by plant roots and fungal hyphae. The stability of microaggregates is also enhanced by multivalent cations which act as bridges between organic colloids and clays. Macroaggregates are enmeshed by plant roots, both living and decomposing, and are thus sensitive to management, and increase in number when grasses are grown and the soil is not disturbed. Lack of root growth,i.e.fallow, has the opposite effect. Various implications for management of soil structure are discussed.