The heavy metal load to Swiss soils decreased significantly in past years. Nevertheless, the input still is considerably higher than crop uptake. Fertilisers contribute around 50 % to the load of most metals, except for chromium and zinc with 90 % and 80 % respectively. Sewage sludge contributes 42 % of the lead, 26 % of the copper and 24 % of the cadmium load but only 9 % of the phosphorus input in fertilisers. In comparison to other fertilisers the quality of mineral fertilisers and manure, expressed as metal to nutrient ratio, is considerably better than that of sewage sludge. Nevertheless, this comparison and an assessment of the ecological relevance of different metals show that the uality of sewage sludge is better than that of compost produced from separately collected organic wastes and of other organic residues used as fertiliser.
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.