The Behaviour of Non-exchangeable Ammonium in SoilsT. Evaluation of Two Methods Determining Non-exchangeable Ammonium in Soils
Li Shcngxiu Zhang Xingchang Zhang Xingwu Tian Xiaohong Hou Gcping(Department of Soil and Agrochemistry)
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.