MINCA "MItigation of Nitrogen pollution at CAtchment scale"

加强农业，特别是化肥的使用，是为不断增长的世界人口确保粮食供应的关键。肥料中所含的氮不仅被植物生物质吸收并最终收获，而且还通过各种气体和水文途径作为活性氮（Nr）释放到环境中。我们假设基于科学的氮减排策略可以在保持产量的同时减少N2O和NH3的排放，减少NO3进入沃茨。因此，MINCA项目的目的是建立一个耦合的，基于过程的水文地球化学模型作为一种工具，用于确定现场管理策略，使之成为可能，以减少氮盈余，从而减少氮污染的农业为主的landscapes.We特别感兴趣的是在界面的领域，地下水，河岸和溪流的氮转换机制。为了克服目前的局限性，了解时间和空间的水文地球化学通量在景观尺度上的NR转换，我们将结合联合收割机创新的实地实验与基于过程的建模方法。然而，在水文地球化学模型中的N循环的表示是复杂的，并且底层过程的验证是数据密集型的。因此，在四个不同的农业，一个草地和一个森林地区进行测量。MINCA由四个紧密相连的工作包（WP）组成。WP1描述了正在进行的测量Vollnkirchener巴赫研究区的水和氮流量。已经比较广泛的连续测量，如N2O排放量，土壤湿度，径流和水质，将通过进一步的测量，如NO3的浸出和浓度，叶面积指数的季节性发展，产量，生物量及其C和N含量来扩展。此外，15N2O和15NO3同位素将在现场活动中测量。WP 1中模型实验的多标准测量和WP 2中基于模型的放大方法将允许WP 3中的参数缩减、不确定性分析和过程可验证性测试。这将有助于确定氮污染在景观中发生的时间和地点，这种深入的知识将成为WP4中制定基于科学的缓解情景的基础。耦合模型在实时数据同化模式下执行，以达到德国联邦粮食和农业部设定的目标值。针对N2O排放和NO3沥滤量的现场实验将证明减缓潜力的有效性。

The intensification of agriculture, and in particular the use of fertilizers, is the key to securing food supplies for a growing world population. The nitrogen contained in the fertilizer is not only absorbed into the plant biomass and finally harvested, but is also released into the environment as reactive nitrogen (Nr) via various gaseous and hydrological pathways. This leads to serious environmental problems such as eutrophication, greenhouse gas emissions or groundwater pollution.We assume that science-based nitrogen mitigation strategies make it possible to reduce N2O and NH3 emissions and reduce NO3 inputs into waters while maintaining yields. The aim of the MINCA project is therefore to establish a coupled, process-based hydro-biogeochemical model as an instrument for identifying field management strategies that make it possible to reduce the Nr-surplus and thus reduce N pollution in agriculturally dominated landscapes.We are particularly interested in the Nr conversion mechanisms at the interfaces of fields, groundwater, riverbanks and streams. In order to overcome the current limitations of understanding the temporal and spatial hydro-biogeochemical fluxes in Nr-transformation on the landscape scale, we will combine innovative field experiments with a process-based modelling approach. However, the representation of the N cycle in hydro-biogeochemical models is complex and the validation of the underlying processes is data-intensive. The measurements are therefore carried out on four different agricultural, one grassland and one forest area. MINCA consists of four closely linked work packages (WP). WP1 describes the ongoing measurement of water and nitrogen flows in the Vollnkirchener Bach study area. The already relatively extensive continuous measurements, e.g. N2O emissions, soil moisture, runoff and water quality, will be extended by further measurements such as NO3 leaching and concentrations, seasonal development of the leaf area index, yields, biomass and their C and N content. In addition, 15N2O and 15NO3 isotopomers will be measured in field campaigns. Multi-criteria measurements for model experiments in WP1 and model-based upscaling methods within WP2 will allow parameter reduction, uncertainty analysis and process plausibility testing in WP3. This will enable to identify when and where N pollution occurs in the landscape.This in-depth knowledge will form the basis for the development of science-based mitigation scenarios in WP4. The coupled model is executed in a real-time data assimilation mode in order to achieve the target values set by the German Federal Ministry of Food and Agriculture. Tailor-made in-situ experiments on N2O emissions and NO3 leaching will demonstrate the effectiveness of the mitigation potential.