Two of our scientists presented their work at the 22nd N Workshop in Aarhus, Denmark
21 June 2024: For one week in June, two scientists of our group spend a fruitful time at the N-Workshop in the wonderful city of Aarhus. The days were filled with talks and poster session about all the different aspects of nitrogen (N) in the agri-food sector. The conference was dealing with the dilemma of ensuring crop productivity and human nutrition through N fertilization, while aiming to decrease N losses leading to environmental pollution and climate change.
Paulina Englert gave a talk about the spatial and temporal variability of nitrous oxide (N2O) fluxes. She presented the results from 1.5 years of field work in the project INFLUX. In the focus of this project stands an Eddy Covariance (EC) Fluxtower equipped with an N2O analyzer, installed at the experimental farm of the University of Göttingen (Reinshof). The results were of big interest for the nitrogen community as EC-N2O measurements have only recently become commercially available and so far, there are only a few towers worldwide measuring N2O on crop lands. The biggest advantage of EC-N2O measurements is the high temporal resolution (half-hourly fluxes all year round). In this way we were able to detect high emission peaks after rewetting or freeze-thaw cycles that can easily be missed with manual chamber measurements but contribute substantially to the annual budget of N2O emission. Additionally, we observed the spatial variability of N2O emission after fertilization at 100 points around the flux tower with a mobile chamber. During one day they varied from 0.5 to 490 μg N2O-N m-2 h-1 and showed a correlation with the spatial variations in soil moisture. This highlights the second advantage of EC-N2O measurements, which is the spatial integration. In the future, EC measurements will help us to better estimate the N2O emissions from agricultural land and develop mitigation strategies.
Dr. Antonios Apostolakis presented an interesting poster about his work of the last 1.5 years in the TRUESOIL project. He explained: “The way we grow our food has serious implications for the environment. For example, shifting the tillage system from inversion ploughing to shallow harrowing is traditionally thought to promote soil organic matter. Could this be used to mitigate climate change? Maybe! But, first, we need to understand how different tillage systems affect greenhouse gas emissions not only today but, in a future, where extreme climatic events, like droughts, will be more frequent.” His results from our long-term tillage experiment Garte-Süd showed that 53 years of reduced tillage did not lead to higher soil organic carbon (SOC) stocks compared to conventional tillage, despite lowering SOC losses as CO2. In contrast, shallow harrowing was associated with a light yield loss and a higher risk of increased N2O emissions, especially under the conditions of a controlled drought experiment. To sum up, soil harrowing did not seem to have a climate change mitigation potential in fine textured temperate croplands.
Contact at the Division Agronomy:
- Dr. Antonios Apostolakis, Tel. 0551 39 25816, antonios.apostolakis@uni-goettingen.de
- Paulina Englert, Tel. 0551-39-25789, paulina.englert@uni-goettingen.de
Dr. Antonios Apostolakis presenting his poster with the title „Soil CO2 and N2O fluxes under wheat and barley in a conventional vs. reduced tillage field trial in Germany”.
Paulina Englert presenting the preliminary results of her PhD thesis in the project INFLUX which deals with the spatial and temporal variability of nitrous oxide fluxes in a German crop rotation .