土壤矿质氮分析方法的影响因素研究

为探明土壤矿质氮分析方法的影响因素,应用采自果园、菜园、麦田、麦田休闲地和草地的5种土样,研究了土样预处理方式、KCl浸提液的保存方式对用连续流动分析仪测定土壤矿质氮具体测定方法的影响。结果表明,土样预处理方式和浸提液保存方式都不同程度地影响土壤中矿质氮的测定结果。方差分析结果进一步表明各种影响因子对土壤硝态氮含量测定值的影响较铵态氮大。采用鲜土直接测定、KCl浸提液不保存直接用连续流动分析仪测定能更准确地反映出土壤矿质氮的实际含量。

Effects of Pretreatment, Shaking and Conserving Method and Extracting Solution on Results for Soil Mineral Nitrogen

There were many methods to analyze soil mineral nitrogen,most of these methods were using extraction directly by chemical reagent.In recent years,extracting methods of soil mineral nitrogen by KCl solution and determining that by continuous flow analyzer were widely used.In order to ascertain factors affecting analytical methods of soil mineral nitrogen,we used five soil samples taken from orchard,vegetable field,wheat field,fallow of wheat field and grassland to study influence of the method with soil pretreatment and conserving method of KCl extracting solution on specific methods by continuous flow analyzer determining soil mineral nitrogen.The results indicated that:soil pretreatment,pore diameter size of sieve used in soil filtered,ratio between solution and soil,shaking time and conserving method of KCl extracting solution exhibited effects on final results in soil mineral nitrogen at different degrees.Analysis of variance indicated that the effects of various factors on measuring results in soil nitrate nitrogen was lager than that on measuring result in ammonium nitrogen.When measuring soil mineral nitrogen,we needed to use directly fresh soil sample and fresh KCl extracting solution daily prepared.It has been noticed that the sample was measured by continuous flow analyzer because real contents of soil mineral nitrogen were more obtained.