What is the effect of a low-protein feed supplement on the ammonia emissions from dairy cattle on pasture? To answer this question, the ammonia emissions from two pasture-based feeding systems with dairy cattle were measured and compared between May and October. In the first system (G) the cows fed exclusively on pasture grass, whilst in the second system (M) 25 % maize silage was supplemented. This resulted in a reduced ratio of protein to energy in the M ration, and correspondingly the amount of excreted nitrogen decreased by around 19 %. The intensive rotational grazing allowed to investigate the temporal dynamics of ammonia emissions. A steady increase was observed during the grazing periods, followed by a relatively quick exponential drop afterwards. Overall, emissions showed only a weak seasonal variation, but significantly lower values (– 40 %) for system M than for system G. The results not only confirm the emission factor for pasture used in the Swiss Inventory, but also show that reduced-protein feed can contribute to a reduction in ammonia emissions.
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.