土壤中非代换铵的行为——Ⅰ.两种测定土壤非代换铵方法优劣的判别

迄今已提出10多种测定非代换铵的方法。但没有一种方法已被证明是可靠的、准确的,原因在于没有衡量测定方法优劣的标准。本文比较了Mogilcvkina与Silva—Brcmncr法对西北地区24种土壤非代换铵的测定结果,并根据非代换的定义及测定过程中出现的问题,提出土壤粘粒,有机质含量与非代换铵关系的密切程度可以作为判断测定非代换铵方法可靠性和准确性的标准。经过检验,证明所提出的判别标准是可行的。根据这一标准,Silva—Brcmncr法优于Mogilcvkina法。

The Behaviour of Non-exchangeable Ammonium in SoilsT. Evaluation of Two Methods Determining Non-exchangeable Ammonium in Soils

Tn this study, the non-exchangeable ammonium of 24 soils from Northwest China were determined by Mogilevkina's and Silva-Brcmncr's methods and a comparison was made to evaluate the results. Based on the definition of non exchangeable ammonium and the problem occurcd during the determination, a criterion is proposed for evaluation of these methods using the relationship between clay content and non-exchangeable ammonium for judging the reliabi'ity and the relation-ship between organic matter content and non-cxchacgcable ammonium for judging the accuracy. This criterion was proved to be practicable and stable by further study. According to this critcrion.Silva-Brcmncr's method is better than Mogilcvkina's one.