EFFECT OF SODICITY, pH, ORGANIC MATTER, AND‐CALCIUM CARBONATE ON THE DISPERSION BEHAVIOR OF SOILS
EFFECT OF SODICITY, pH, ORGANIC MATTER, AND‐CALCIUM CARBONATE ON THE DISPERSION BEHAVIOR OF SOILS
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DOI：
10.1097/00010694-198404000-00006
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发表时间：
1984-04
期刊：
影响因子：
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通讯作者：
R. Gupta;D. Bhumbla;I. Abrol
中科院分区：
文献类型：
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作者：
R. Gupta;D. Bhumbla;I. Abrol
过量的交换性钠已知会对土壤的物理性质产生不利影响。钠吸附比（SAR）仅考虑了阳离子，忽略了引起碱的阴离子，被广泛用作衡量土壤碱度和粘土分散等相关物理现象的指标。在CaCO3存在下，过量的交换性钠导致苏打土pH值升高。高pH值伴随高土壤碱度对土壤物理性质的影响通常被忽视。本研究的目的是评估碱度和pH值的分散行为的一个代表性的土壤中的CaCO3和有机质的相对作用。在这项研究中，均离子钠饱和土壤被用来研究分散在盐浓度的各种碱度（pH 6.0至10.8）和SAR（5至100）的解决方案。研究表明，增加碱度（pH）或SAR增加粘土分散。发现碳酸钙和高电解质浓度对分散非常有效。在腐殖物质的存在下，碱度的积累急剧提高粘土分散。SAR大于15至20的有机物的添加也增加了分散。我们讨论的结果，其实际意义下的自然条件下，具有高碱度和高pH值的碱性土壤。
Excess exchangeable sodium is known to adversely affect soil's physical properties. Sodium adsorption ratio (SAR), which takes into account only the cations, ignoring the alkali-causing anionic species, has been widely used as an index of sodicity and related physical phenomena of clay dispersion, etc. In the presence of CaCO3, excess exchangeable sodium results in high pH of sodic soils. The effect of high pH accompanying high soil sodicity on the physical behavior of soil has generally been overlooked. The objective of the present study was to evaluate the relative role of sodicity and pH on the dispersion behavior of a representative soil in relation to CaCO3 and organic matter. For this study homoionic sodium-saturated soils were used to study dispersion in salt-concentration solutions of various alkalinity (pH 6.0 to 10.8) and SAR (5 to 100). The study revealed that increasing alkalinity (pH) or SAR increased the clay dispersion. Calcium carbonate and high electrolyte concentration were found to be very effective against dispersion. An alkalinity buildup in the presence of humic substances sharply enhanced the clay dispersion. Additions of organic matter at SAR more than 15 to 20 also increased dispersion. We discuss the results for their practical implications under the natural conditions of alkali soils having both high sodicity and high pH.