Thesis subject

Effects of mitigation options and changing diets on nitrogen and phosphorous losses to the environment

The Environmental Systems Analysis Group provides the possibility for students to do their thesis in collaboration with our group. This is one of many possible thesis subjects. Please feel free to contact professors De Vries and Kroeze (right) for more information.

On average, the effective consumption of nitrogen (N) and phosphorous (P) inputs by fertilisers used in agriculture, is only about 10-15% at global scale. The remaining 85-90% is lost to the environment, causing acidification, eutrophication, global warming, nitrate in ground water and tropospheric ozone (smog). Key mitigation options to reduce agricultural requirements of N and P include the improvement of N and P use efficiency (NUE and PUE) in crop and animal production systems, the reduction of food waste in households, and lower consumption of N and P intensive products like meat. It is well known that it takes more N and P to produce 1 kg meat than 1kg of arable products. Nevertheless, in most world regions the human diets are changing over time towards more meat consumption, which could strongly off set potential increases in NUE and PUE in the whole food chain along crop and animal production systems and reduction of food waste.

This thesis subject addresses two questions:

  1. What is the effects of changing diets on the release of nutrients (specifically nitrogen and phosphorous in the environment), and
  2. How can we assess the overall environmental impact of human diets, as compared to measures increasing NUE and PUE?