臺灣酸性土壤酸度強度特性之研究（一）測定法之比較

The Intensity Characteristics of Soil Acidity in Taiwan Acid Soils (1) Comparison of Measuring Method

林紫慧(Tzu-Huei Lin) ； 陳啟烈(Chi-Lieh Chen) ； 洪崑煌(Kun-Huang Houng)

《土壤與環境》 2卷3期 (1999/09) Pp. 265-280

https://doi.org/10.30058/SE.199909.0008

摘要

The soil pH is not only the most important characteristics of the soil, it is also the most widely used chemical index of soil. However, the soil pH has long been considered as the most difficult index to be determined precisely. Six series of representative acid soils of Taiwan were studied in this article, Chiwulan, Lungkang, Potu, Pinchen, Tansui, and Laopi. The pH values of solutions and sediments were measured in water (pH(subscript W)), 0.01 M CaCl2 (pH(subscript Ca)) or 1 M KCI (pH(subscript K)) with solution to soil ratios at 1, 2.5, 5, 10 or saturated paste after mixing for 16 hours. Suspension effect was most pronounced in water suspensions, followed by the suspensions in CaCl2 solution and, then KCl solution. The pH(subscript W) values were found to increase with solution-to-soil ratio, and the difference between pH values of solution-to-soil ratios at 10:1 and saturation paste (dpH(subscript W)) increases with EC values of saturation pastes. The pH(subscript K) values were also found to increase with the solution-to-soil ratios, while the dpH(subscript K) values decrease with the pH(subscript K) (1:1) values. In this study, the pH(subscript Ca) was indifferent to the solution-to-soil ratio. The pH values of all treatments were highly correlated to each other. The values of pH(subscript W) were higher than pH(subscript Ca) and then, pH(subscript K). It was also found that the lime potential measured by three different methods were all identical. We conclude that pH value measured in 0.01 M CaCl2 solution is a better soil acidity index unaffected by solution-to-soil ratios.

關鍵字

臺灣酸性土壤 ； 土壤pH值 ； 石灰位能 ； 土壤酸度強度

並列摘要

The soil pH is not only the most important characteristics of the soil, it is also the most widely used chemical index of soil. However, the soil pH has long been considered as the most difficult index to be determined precisely. Six series of representative acid soils of Taiwan were studied in this article, Chiwulan, Lungkang, Potu, Pinchen, Tansui, and Laopi. The pH values of solutions and sediments were measured in water (pH(subscript W)), 0.01 M CaCl2 (pH(subscript Ca)) or 1 M KCI (pH(subscript K)) with solution to soil ratios at 1, 2.5, 5, 10 or saturated paste after mixing for 16 hours. Suspension effect was most pronounced in water suspensions, followed by the suspensions in CaCl2 solution and, then KCl solution. The pH(subscript W) values were found to increase with solution-to-soil ratio, and the difference between pH values of solution-to-soil ratios at 10:1 and saturation paste (dpH(subscript W)) increases with EC values of saturation pastes. The pH(subscript K) values were also found to increase with the solution-to-soil ratios, while the dpH(subscript K) values decrease with the pH(subscript K) (1:1) values. In this study, the pH(subscript Ca) was indifferent to the solution-to-soil ratio. The pH values of all treatments were highly correlated to each other. The values of pH(subscript W) were higher than pH(subscript Ca) and then, pH(subscript K). It was also found that the lime potential measured by three different methods were all identical. We conclude that pH value measured in 0.01 M CaCl2 solution is a better soil acidity index unaffected by solution-to-soil ratios.

並列關鍵字

Taiwan acid soil ； Soil pH ； Lime potential ； Intensity of soil acidity