一种可用于评估土壤团聚体稳定性的超声能量法

Application of Ultrasonic Energy for Assessing Aggregate Stability

团聚体稳定性是土壤质量的重要指标。鉴于当前团聚体稳定性难以定量的研究现状,本文提出一个可定量评估土壤团聚体稳定性的超声能量法,并与传统Yoder湿筛法对比分析了稳定性土样（浙江潮土、重庆黄壤土、江西红壤）和弱稳定性土样（河北壤土和黑龙江暗棕壤）五种典型土壤的5～3mm粒级团聚体的平均重量直径（MWD）和团聚体粒径分布（ASD）。结果表明：（1）测试土样的稳定性为潮土〉红壤〉黄壤土暗棕壤〉壤土;（2）超声能量法分散强度大,分散效率高,更适用于稳定性土样的评估,对于弱稳定性土样的评估则不如传统Yoder湿筛法。因此,评估土壤团聚体稳定性时可以选择合适的测量方法以提高分辨精度,即强稳定性土壤对比分析应选用超声能量法,而弱稳定性土壤对比分析则可以用Yoder湿筛法。

Aggregate stability is an important index of soil quality,but hard to be quantified.Here an ultrasonic energy method was developed to quantify soil aggregate stability,and its practicability was tested by comparing with Yoder method in terms of mean weight diameter（MWD）and aggregate size distribution（ASD）of two groups of soils,3stable soils（Fluvo-aquic soil from Zhejiang Province,Yellow loam from Chongqing City,Red soil from Jiangxi）and 2 weak soils（Loam from Hebei Province,Dark brown soil from Shangdong Province）.The results show that the stability indicated by MWD decreases in the order：Fluvoaquic soil〉Red soil 〉Yellow loam〉〉Dark Brown soil〉Loam;the ultrasonic dispersion cam break soil aggregate efficiently due to its strong dispersing power,and thus this method prefers to strong soil than Yoder method,but this method seems not to be suitable to assess the aggregate stability of weak soil compared with Yoder method.Therefore,aproper method assessing soil aggregate stability can be chosen through the rule：ultrasonic energy method for stable soil,Yoder method for weak soil.