关于自动凯氏定氮仪用于测定土壤碱解氮的疑问与验证  

Determination of Soil Alkaline Hydrolytic Nitrogen by Automatic Kjeldahl Azotometer:Questions and Verification

作　　者：杨爽 杨春蕾 YANG Shuang;YANG Chunlei(The Biology and Technique Center of Tibet Agriculture and Animal Husbandry College,Nyingchi,Tibet 860000;Lhasa Agriculture and Animal Husbandry Bureau,Lhasa 850000)

机构地区：[1]西藏农牧学院资源与环境学院,西藏林芝860000 [2]西藏拉萨市农牧局,拉萨850000

出　　处：《中国农学通报》2023年第14期67-73,共7页Chinese Agricultural Science Bulletin

基　　金：西藏自治区自然基金项目“林芝河谷地区典型设施农田氮磷累计特征及面源污染评价”(ZRKX2021000024)。

摘　　要：随着现代仪器的迅速发展,诸多研究认为采用自动凯氏定氮仪可以代替碱解扩散法测定土壤碱解氮,对此笔者有一些疑问。为了解开这些疑惑,也为了进一步研究自动凯氏定氮仪用于测定土壤碱解氮的可行性,笔者进行了验证实验。用自动凯氏定氮仪和传统方法测定自制土壤样品碱解氮含量,并分析2种方法测定结果之间的相关性和差异性,以及硝态氮测定结果的准确性。结果表明:在设定的试验条件下,无论加与不加还原剂,2种方法的测定结果均呈极显著相关关系,但75%以上的土壤样品测定值具有显著差异性;与碱解扩散法相比,自动凯氏定氮仪测得的结果与硝态氮含量相关程度更高。自动凯氏定氮仪测定的“土壤碱解氮”不能等同于碱解扩散法测定的“土壤碱解氮”,但其测定结果仍可以作为一个新的测定指标,应用于生产实践。With the developing of modern analytical instruments,a new method was adopted to analyze the value of soil alkaline hydrolytic nitrogen by using the Kjeldahl apparatus instead of alkali solution diffusion method.The similarities and differences between the results of the two methods should be clarified.So the verifying experiment in which automatic Kjeldahl nitrogen azotometer was used to determine the value of alkaline hydrolytic nitrogen of soil was carried out.The content of alkaline hydrolytic nitrogen in soil was determined by both automatic Kjeldahl azotometer and the traditional method,and the correlation and difference of the two methods,as well as the accuracy of nitrate nitrogen determination were analyzed.The results showed that over 75%of the soil samples had significantly different testing values with or without reducing agent under the two methods.Meanwhile,there was a significantly positive correlation between the results of the two methods.The results obtained by automatic Kjeldahl azotometer had higher correlation with the content of nitrate nitrogen than the traditional method.In summary,the soil alkaline hydrolytic nitrogen measured by automatic Kjeldahl azotometer could not be equated to that measured by alkali solution diffusion method,but the testing result still can be taken as a new index for measurement and applied in actual soil analysis.

关 键 词：土壤 碱解氮 硝态氮 自动凯氏定氮仪 碱解扩散法 

分 类 号：S151.95[农业科学—土壤学]