1,1,2,3,3,1,4- 1Bioclimatology, University of Göttingen, Göttingen, Germany
- 2Division of Agronomy, University of Göttingen, Göttingen, Germany
- 3Environment Modeling Group, University of Bonn, Bonn, Germany
- 4Centre of Biodiversity and Sustainable Land Use, University of Göttingen, Göttingen, Germany
The management of cropping systems can substantially impact the amount of CO2 emitted, such as during fertilisation, tillage and bare soil conditions. Smart and optimised management practices can promote sustainable farming allowing for maximum yields and fertile soils at the same time. This study aims to investigate the impact of management interventions on CO2 and energy fluxes at a cropland site in central Germany.
In our study, continuous CO2, water, and energy fluxes have been measured at the Reinshof (DE-Rns; 51°29'24.0"N, 9°55'55.2"E) agricultural FLUXNET site near Göttingen, Germany, since 2021. The field is conventionally managed, with a typical crop rotation (winter barley, sugar beet, winter wheat), deep tillage and received both organic and mineral fertilisation. Measurements are performed at a 6.5 m tall flux tower equipped with an eddy covariance setup (uSONIC3-omni Cage MP, METEK; LI7200, LI-COR) for CO2, water, and energy fluxes, as well as ancillary meteorological instruments.
The results indicate that gross primary productivity and ecosystem respiration were the highest during the cultivation of sugar beet compared to all cereals grown in the other years (wheat and barley), with values that were 20% and 6% higher, respectively. This resulted in a 50% higher net ecosystem productivity. Evapotranspiration was 21% higher than for the other crops. The high productivity of sugar beet in terms of carbon and ET fluxes can be explained by (i) its high natural efficiency in sequestering carbon, (ii) the extended growing season and (iii) the higher leaf area index compared to cereals (wheat or barley). Despite the higher fluxes, the annual water use efficiency of sugar beet was similar to that of wheat and barley. Furthermore, we demonstrate that bare soil conditions lead to carbon losses, which could be mitigated through the extended cultivation of cover crops.
In conclusion, both management and crop rotation had the greatest impact on the variability of annual carbon and evapotranspiration budgets, suggesting that management plays a relevant role in carbon and water fluxes in croplands and can be used to increase the carbon uptake.
How to cite: Markwitz, C., Emad, A., Englert, P., Meijide, A., Münter, C., Tunsch, E., and Knohl, A.: CO2, water and energy fluxes over a cropland in central Germany, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-7237, https://doi.org/10.5194/egusphere-egu26-7237, 2026.
