不同目数筛网对土壤有机质测定的影响研究

Effects of Different Soil Sample Preparation Processes on the Determination of Soil Organic Matter

摘要: 本文以嘉陵江流域照壁沟村不同海拔高度及不同剖面深度的土壤为对象，研究其在水合热重铬酸钾氧化–比色法测定土壤有机质时，不同筛目下的土壤样品对有机质测定结果的影响。研究结果表明：过目数越小的土壤样品，所测得的有机质数量越大；不同目数土粒样品中，植物根系的残留对土壤有机质的测定影响显著；在同粒径土壤样品中，表层土壤(10 cm)有机质土粒含量较深层(30 cm)高。

Abstract: We have chosen soil at different altitudes and sampling depths as the research object to analyze soil organic matter content in Jialing river basin of Shun Qing in Nan Chong. In this study, hy-drated hot potassium dichromate oxidation-colorimetric method was used to determine soil organic matter. Soil samples with different sieves were used to study the influence of soil prep-aration process on soil organic matter determination. The results showed that the smaller the soil particle is, the lager the special surface area is, and soil sample can be dissolved by potas-sium dichromate solution completely and oxidized by concentrated sulphuric acid thoroughly, and then we can determinate a higher soil organic matter content. The results also showed that the plant roots in the surface soil layer (10 cm) are more than middle soil layer (30 cm), and ef-fects of plant roots on the determination of soil organic matter in surface soil are more re-markable than that in intermediate soil.