土壤pH值实验室测定过程中影响因素的探讨

Discussion on the Influential Factors of Soil pH Value in Laboratory Determination

土壤pH值是土壤酸碱强度的指标,是土壤的基本性质之一,由于土壤成分复杂且内部处于不断交换的过程,其pH值的准确测定较为困难,因此展开影响因素的逐一研究对其pH值的准确测定有着重要意义。本文就实验室玻璃电极法测定土壤pH值过程中的几个重要影响因素展开实验并研究讨论。结果表明,陈化时间对实验室测定土壤pH值影响较大,20天以上的陈化能使土壤pH值稳定;不同方式处理实验用水浸提所测得的土壤pH值基本无差别;浸提时间对样品的测定有很大的影响,应尽量选择浸提时间在30~60 min;液土比过小则浸提液少,过大则稀释效应显著,均不利于pH值的准确测定,通常选择选择液土比为2.5∶1。

Soil pH,the indicator of acid-base strength,is one of the basic properties of soil.The accurate measurement of soil pH is affected by numerous factors due to the complexity of soil components and its constantly exchange.In this paper four important factors affecting soil pH value in the process of testing with glass-electrodes method in lab were discussed,respectively.The results showed that the aging time had a great influence on the soil pH value and 20 days can stabilize the pH well.Besides,the soil pH measured by two kinds of extracting water were basically the same,the extraction time had an impact on the determination and an extraction time of 30 min to 60 min was preferred.Finally,the liquid-soil ratio should be reasonably chosen to eliminate over saturation and dilution effect,which is generally suggested adopting 2.5∶1.