Concepts of circularity demand that nutrient flows are circular, with a minimum amount of loss. For nitrogen (N), the atmosphere is a part of the natural cycle and full circularity is not possible. Currently, main N sources for Dutch agriculture are imports with food and feed and N fertilizer derived from natural gas. Shifting from fossil-fuel derived N extraction from the atmosphere to biological N-fixation comes with trade-offs in terms of the area of land needed for production of feed and food. A more circular agriculture, with an elimination of fossil fuels combined with the required reduction of greenhouse gas (GHG) emissions demands an alternative source of N in agricultural systems. Trade-offs in the system are important to consider. For example, lowland peat in the Netherlands are mostly eutrophic and when mineralised can freely provide about 200-300 kg N ha-1 y-1. Grass produced on these peatlands on dairy farms provide a substantial input to the agricultural system. But this comes at the expense of carbon dioxide losses from peat decomposition. Peatlands are not needed for food production when reducing intake of proteins from animal products (Van Kernebeek et al., 2016), and rewetting peatlands can substantially reduce GHG emissions. Yet producing milk from clay and sandy soils require more fertilizer from fossil fuels per unit of production. But what if only legume-N is available, what are then the land area requirements and what crops can be produced in such crop rotations? What are the prospects of N production from green energy sources?
In this project, we aim to quantify and evaluate trade-offs for various alternatives that are (or may become) available. How do alternatives compare in terms of the area of land required per capita and associated GHG emissions under a scenario for circular agriculture? How important is the location of production, i.e. how is location of production affecting efficiency and productivity and associated trade-offs? Are best options different for soils with a very high production potential in the Dutch delta compared to soils with a lower production potential in e.g. Eastern Europe?
De Boer & van Ittersum, 2019. Circularity in agricultural production. Wageningen University.
Conijn et al. 2018. "Can our global food system meet food demand within planetary boundaries?" 251: 244-256.
Schils et al., 2018. Cereal yield gaps across Europe. 101: 109-120.
Van Kernebeek et al 2016. Saving land to feed a growing population: consequences for consumption of crop and livestock products. 21(5): 677-687.
A successful completion of the course Analysing Sustainability of Farming Systems or QUALUS. Ability to use R or a strong interest in learning it is required.
Tom Schut firstname.lastname@example.orgMartin van Ittersum0317-482382Martin.email@example.com