Denitrification in relation to soil nitrite and nitrate dynamics – towards source differentiation in undisturbed soil

在DASIM第一阶段，项目P5的重点是在实验室实验中对有热点和无热点的重填土壤同时发生的总氮动态进行表征。为了提高氮通量测量的灵敏度，开发了一种在低氮气氛下的实验室培养方法。不同的标记选项，包括15 N三重标记方法，双重18 O-15 N标记和同位素异构体研究平行进行，目前正在进行评价。在第二阶段（本申请），测量将转移到现场。P5负责在永久性草地上进行的中心实验CE-GI，其中第一阶段测试和开发的方法将在田间条件下进行。P5将测试和开发合适的标记技术，并将在实地进行18 O标记研究以及土壤芯研究，以支持实地数据。CE-GI将与大多数P互动，并与PC密切合作，开发用于分析DASIM内生成的数据集的数值分析技术。将与P1合作评价吉森土壤的土壤结构。获得的完整数据集将作为DASIM RU P7和P8中开发的模型的验证数据。

In DASIM phase I the project P5 focused on the characterization of the simultaneously occurring gross nitrogen dynamics in laboratory experiments with repacked soil with and without hot spots. A laboratory incubation method at reduced N2 atmosphere was developed and carried out to increase the sensitivity of N2 flux measurements. Different labeling options, including the 15N triple labelling method, dual 18O-15N labelling and isotopomer studies were carried out in parallel and are currently evaluated. In phase II (this application) measurements will move to the field. P5 is responsible for the central experiment CE-GI on permanent grassland where the methods that were tested and developed in phase I will be carried out under field conditions. P5 will test and develop suitable labeling techniques and will also carry out 18O labelling studies in the field as well as soil core studies to support field data. CE-GI will interact with most P’s and cooperates intensively with PC to develop numerical analysis techniques for the analysis of data sets generated within DASIM. The soil structure of the Giessen soil will be evaluated in collaboration with P1. Full data sets obtained will serve as validation data for the models developed in P7 and P8 of the DASIM RU.