激光粒度仪与沉降一吸管法测定褐土颗粒组成的比较

土壤颗粒组成是土壤的基本物理属性之一,沉降—吸管法是传统土壤颗粒分析的主要方法,激光粒度仪法是近年来新兴的粒度分析方法。为了研究二者的差异,选取了23个黏粒含量差异较大的褐土样品,采用上述两种方法对土样进行了分析。结果表明:激光粒度仪检测<0.002mm颗粒含量低于吸管法,但二者有较好的相关性,决定系数为0.97;在检测<0.02mm颗粒含量时两者比较接近,并且相关性很好,决定系数为0.99;检测<0.05mm颗粒含量时两者也比较接近,决定系数为0.91。激光粒度仪检测结果通过转换模型修正后,可以较好地反映褐土土壤颗粒组成情况。

Comparison of Determination on Grain Size of Cinnamon Soil by Laser Diffraction Particle Size Analyzer and Pipette Method

The particle-size composition is a basic soil physical property.Pipette method is a main traditional approch to analyze the soil particle-size composition while laser diffraction particle size analyzer is a new particle-size analysis instrument in recent years.The paper took 23 cinnamon soil samples with various clay particle contents to study the discrepancy between the two methods mentioned above.It shows that the results from laser diffraction particle size analyzer method are lower than pipette method when measuring the particle-size <0.002 mm while they have a good correlation with a determination coefficient of 0.97;when it comes to<0.02 mm particle-size,the results come close and have a strong correlation with a determination coefficient of 0.99;when measuring particle content<0.05 mm,they come very close with a determination coefficient of 0.91.The results from laser diffraction particle size analyzer can reflect the soil particle-size composition well if they get revised by a transformational model.