不同前处理条件对土壤NO_3-N、NH_4-N含量影响的研究

Effects of Pretreatment on Content of Soil NO_3-N,NH_4-N

采用大棚土壤,研究了土样预处理方式、KCl浸提液浓度和液土比对用连续流动注射分析仪测定的土壤NO3-N、NH4-N含量的影响。结果表明,土壤预处理方式、KCl浸提液浓度和液土比都不同程度影响土壤NO3-N、NH4-N的含量测定结果。风干、烘干的土样预处理方式对土壤NH4-N、NO3-N含量测定有显著影响,表现为新鲜土<风干土<烘干土;用2mol/LKCl溶液作为浸提液,液土比5∶1(V∶V)测定大棚NO3-N含量,测定结果稳定。

Extracting methods of soil NO3-N, NH,-N by KCl solution and determining that by continuous tlow analyzer were respectively used. There were many factors to influence results of soil NO3-N, NH4-N, such as soil pretreatment, concentration of KCl extracting solution and ratio of solution to soil and so on. In the paper, effects of these factors on content of soil NO3-N, NH4-N in greenhouse soil were studied. The results showed that： concentration of soil NO3-N, NH4-N in greenhouse had significant changes during air-drying and heat-drying, and contents of NO3-N, NH,-N in fresh soils was lower than air-dried soils and beat-dried soils. When 2 mol/L KCI extracting solution was used and the ratio of solution to soil is 5：1, determined results of soil NO3-N, NH4-N in greenhouse were more accurate. But fit extracting concentration and ratio of solution to soil must be selected according to the goal of the research.