Renewing agricultural grasslands for improved yields and forage quality generally involves eliminating standing vegetation with herbicides, ploughing and reseeding. However, grassland renewal may negatively affect soil quality and related ecosystem services. On clay soil in the north of the Netherlands, we measured grass productivity and soil chemical parameters of ‘young’ (5–15 years since last grassland renewal) and ‘old’ (>20 years since last grassland renewal) permanent grasslands, located as pairs at 10 different dairy farms. We found no significant difference with old permanent grassland in herbage dry matter yield and fertilizer nitrogen (N) response, whereas herbage N yield was lower in young permanent grassland. Moreover, the young grassland soil contained less soil organic matter (SOM), soil organic carbon (C) and soil organic N compared to the old grassland soil. Grass productivity was positively correlated with SOM and related parameters such as soil organic C, soil organic N and potentially mineralizable N. We conclude that on clay soils with 70% desirable grasses (i.e., Lolium perenne and Phleum pratense) or more, the presumed yield benefit of grassland renewal is offset by a loss of soil quality (SOM and N-total). The current practice of renewing grassland after 10 years without considering the botanical composition, is counter-productive and not sustainable.
MULTIFILE
Direct Air Capture (DAC) technology is necessary to help achieve the EU's 2050 climate goals, since it allows for net-negative emissions. This will be needed to offset historic emissions while working alongside with other CCU technologies. To make DAC technology truly effective, the carbon footprint of the process itself should be as low as possible. This project describes research plans to minimize the DAC carbon footprint (as well as cost per ton of CO2) by developing technology to maximize DAC filter lifetimes. The project outlines a strategic partnership between Skytree, a Dutch DAC start-up, and Dr. Baumgarter’s research group at the University of Amsterdam. Based on Life Cycle Analyses (LCA) performed by Skytree, they have identified that extending the lifetime of DAC filters can lower the overall carbon footprint by 35%. Similarly, Techno-Economic Assessment indicated that this increased lifetime could lower the cost per ton of CO2 by 10%. To achieve this, both parties will develop an indicator technique to accurately describe filter lifetime to allow for data-driven optimized filter maintenance. The indicator development will expand on a patented technology developed by Skytree. The current technology uses a colorimetric dye to qualitatively assess filter capacity. By gaining access to advanced analytical methods built at UvA, this technology can be enhanced to allow for quantitative sorbent capacity and thus lifetime predictions. Since Dr. Baumgartner’s group specializes in building innovative spectroscopic technique that can monitor functional materials during gas sorption processes, the proposed studies will be able to directly and accurately link sorbent capture performance (using IR spectroscopy) with indicator dye intensity (using UV-Vis spectroscopy). This will allow for the fast development of a calibrated filter lifetime indicator. This makes the foreseen research highly practical and impactful, as the results will directly be implemented in commercial DAC/CCU technology.