用pH—pCa电极对直接测定土壤的石灰位

Direct Measurement of Soil Lime Potential with pH-pCa Elecrode Couple

石灰位定义为pH—0.5pCa。与pH值相比较,石灰位能更全面地反映土壤的酸性强度。讨论了用pH玻璃电极和PVC膜钙电极(以ETH1001为载体)测定石灰位的原理和方法。研究了土壤中的含盐量、氧化铁、有机质以及水土比对土壤石灰位测定的影响。给出了中国黄壤、黄棕壤、红壤和砖红壤的旱地及水稻土的石灰位的测定结果。根据大量的实验结果,对我国南方主要酸性土壤的酸性强度作了分级。

The lime potential is defined as pH-0. 5pCa, In comparison with the pH, the lime potential can more overally be used to characterize the acidic strength of a soil . The principle and the metheod for determing the lime potential in soil with pH glass electrode and PVC membrane calcium ISE is described. The neutral carrier ETH 1001 is used as the electroactive materal calcium ISE, The effect of the content of total salt , the ferric oxide,the organic matter, and of the ratio betweem the weights of soil and water on the determination of lime potential is studied. A series of results of lime potential obtained from the yellow earth,the yellow browm earth,the red earth and the laterite in China are listed. According to a large amount of experimental data,the gradation on the acidic stength of main acid soils in Saouth China ate doing.