Poind Soil pH Measurement
Poind Soil pH Measurement
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DOI：
10.1111/j.1749-7345.2001.tb01089.x
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发表时间：
2001-06
影响因子：
2.8
通讯作者：
Taworn Thunjai;C. Boyd;K. Dube
中科院分区：
文献类型：
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作者：
Taworn Thunjai;C. Boyd;K. Dube
土壤 pH 值通常通过水产养殖池底部的样品进行测量。使用几种不同的土壤 pH 值技术。这项研究考虑了不同方法获得的 pH 值的差异，并确定了哪种方法最有用。当插入干燥土壤和蒸馏水 1:1 的混合物中时，双电极（指示电极和参比电极）和单探针组合电极给出相似的 pH 值。当双电极布置为指示电极处于混合物的沉积相而参比电极处于混合物的上清液相时，双电极和组合电极的读数之间存在轻微的差异。使用双电极的两相方法似乎没有必要，因为测量难度更大。干燥土壤与蒸馏水的比例为 1:2.5、1:5 和 1:10 时，其 pH 值逐渐高于 1:1 比例时的 pH 值。在 0.01 M CaCl2 和 1.0 M KCl 中进行的测量与在蒸馏水中进行的测量具有很大不同的值。当在不搅拌的情况下测量 pH 值或在土壤-水混合物的滤液中测量 pH 值时，会产生较高的 pH 值。为了获得稳定的 pH 值，测量前需要间歇搅拌 20 分钟。粒径不会影响通过 0.053 至 2.36 毫米筛子的等分试样的 pH 值。干燥温度对 pH 值有很大影响，在 40 至 60°C 干燥的样品上进行的测量可能是最可靠的。使用标准 pH 电极或便携式酸度测试仪测量湿土壤中的原位 pH 值与在 1:1 干土壤与蒸馏水混合物中进行的测量有很大不同。池塘底土pH测量应标准化。根据本研究的结果，建议采用以下方法：在强制通风烘箱中于 60°C 下干燥土壤；将土壤粉碎，过2毫米筛；将土壤和蒸馏水按 1:1 的比例（重量：体积）混合；用玻璃棒间歇搅拌30分钟；将双电极或组合电极插入混合物中；搅拌时测量 pH 值。
Soil pH often is measured in samples from the bottoms of aquaculture ponds. Several different techniques for soil pH are used. This study considered the differences in pH obtained by the different methods and determined which methods appeared most useful. Dual electrodes (indicating and reference) and a single-probe combination electrode gave similar pH values when inserted into 1:1 mixtures of dry soil and distilled water. There were slight differences in pH between readings with dual and combination electrodes when the dual electrodes were arranged with the indicating electrode in the sediment phase and the reference electrode in the supernatant phase of the mixture. The two-phase method with the dual electrode does not appear warranted because of greater difficulty in making measurements. Dry soil: distilled water ratios of 1:2.5, 1:5, and 1:10 had progressively greater pH readings than obtained at a 1:1 ratio. Measurements made in 0.01 M CaCl2 and 1.0 M KCl had much different values than those made in distilled water. Higher pH resulted when pH was measured without stirring or in filtrates of soil-water mixtures. A 20-min period of intermittent stirring before making measurements was necessary for a stable pH value. Particle size did not influence pH in aliquots passing 0.053 to 2.36-mm sieves. Drying temperature had a strong influence on pH, and measurements made on samples dried at 40 to 60 C are probably most reliable. Measurements of in situ pH in wet soil with standard pH electrode or a portable acidity tester differed greatly from those made in 1:1 dry soil to distilled water mixtures. Pond bottom soil pH measurement should be standardized. Based on findings of this study, the following method is suggested: dry soil at 60 C in a forced-draft oven; pulverize soil to pass a 2-mm sieve; mix soil and distilled water in a 1:1 ratio (weight: volume); stir intermittently with glass rod for 30 min; insert dual electrodes or a combination electrode into the mixture; measure pH while stirring.