A climate-soil strategy
Grass hardly looks like a technological solution to climate change. It grows beside roads, between fields and across millions of hectares of European countryside. Yet its apparent simplicity hides something interesting. Modern agriculture has increasingly specialised in annual crops, and that intensification has come with a legacy of depleted soil carbon, nutrient losses, erosion and other environmental pressures. What would happen if perennial grass were deliberately brought back into crop rotations—not simply as another crop, but as part of the environmental infrastructure of agricultural landscapes? This was the question behind our study, Large-scale deployment of grass in crop rotations as a multifunctional climate mitigation strategy. Instead of looking at a handful of experimental fields, we modelled more than 81,000 sub-watersheds across the EU27 and the United Kingdom, asking where additional grass could make sense and what it might achieve.
The interesting part is that the answer is not only about carbon. Bringing perennial grass into rotations could help rebuild soil organic carbon while simultaneously producing large quantities of biomass and protein. The same change could reduce nitrogen losses to water, limit wind and water erosion and, in some landscapes, contribute to flood mitigation. If some of the harvested grass were processed in green biorefineries, it could also become feed protein, biogas and raw material for other biobased products. In the scenarios explored in the study, the combined annual greenhouse-gas savings from soil-carbon sequestration and replacing natural gas with grass-derived biogas were estimated to be equivalent to roughly 13–48% of current greenhouse-gas emissions from European agriculture. This is not a prediction that such savings will automatically occur: it is a modelled estimate of the scale of the opportunity under widespread deployment. But it reveals an important point. A hectare of agricultural land does not necessarily have to deliver just one service. Managed differently, the same landscape can produce commodities while also storing carbon, protecting soils and improving water quality.
There is, of course, a catch—and it may be the most interesting part of the story. Growing grass is easy; creating an economic system that values everything the grass does is much harder. Farmers need markets for the biomass, biorefineries need investment and reliable supply chains, and environmental benefits such as carbon sequestration or cleaner water need mechanisms that translate them into real incentives. The study therefore points beyond a simple choice between food production and environmental protection. The challenge is to design agricultural and bioeconomy systems in which the two reinforce one another. In that sense, grass becomes more than a crop: it becomes a possible bridge between agriculture, renewable energy, soil restoration and the emerging circular bioeconomy. This connection between biomass production and the wider functions of landscapes is also central to research at the Biomass Production. Further publications and research activities are available here.
Co-benefits of introducing grass production in crop rotations with the primary objective of enhancing soil organic carbon. The figure shows the relative to contribution toward reaching the classification “low impact” at the landscape scale for nitrogen emissions to water, soil loss by water erosion, and soil loss by wind erosion, respectively, in the low-estimate (left) and high-estimate (right) scenarios. Landscapes that already have a “low” or lower impact are excluded.
Read the study
Englund, O., Mola-Yudego, B., Börjesson, P., Cederberg, C., Dimitriou, I., Scarlat, N., & Berndes, G. (2023). Large-scale deployment of grass in crop rotations as a multifunctional climate mitigation strategy. GCB Bioenergy, 15(2), 166–184.
Full-text article:
Open-access PDF
Journal:
GCB Bioenergy — Wiley
Article page:
Wiley Online Library
DOI:
https://doi.org/10.1111/gcbb.13015
0 comments:
Post a Comment