The phosphorus concentration in the Greifensee continues to exceed the target value, due to excessive phosphorus inputs. No relevant water pollution by nitrogen is currently evident. Phosphorus and nitrogen inputs from diffuse sources have been estimated with the aid of the Modiffus model. High phosphorus inputs are principally due to leaching of drained arable land, soil erosion from arable land and run off from grassland. High nitrogen inputs are the result of leaching and drainage losses from arable land. Further model calculations show the potential for reducing phosphorus pollution. Measures by farmers will not reduce phosphorus inputs sufficiently in the medium term to reach the target value for the Greifensee.
A comparison of different methods of winter-wheat fertilisation with nitrogen showed that nitrogen surpluses can be significantly reduced by means of site-specific variable-rate nitrogen fertilisation.
Fabian Y., Roberti G., Jacot K., Gramlich A., Benz R., Szerencsits E., Churko G., Prasuhn V., Leifeld J., Zorn A., Walter T. (ꝉ), Herzog F.
Many tile drainage systems on arable land are in need of renewal. Cantons and stakeholders will now be given a decision-making tool enabling them to assess such areas in detail and to find sustainable solutions.
Ammonia emissions from the Swiss farming sector have scarcely declined over the past 20 years. This is because the factors leading to either an increase or decrease in emissions have for the most part cancelled each other out between 2000 and 2020.