The impact of drought on forage production in Switzerland, and farming practices to cope with water scarcity

In Switzerland, grassland takes up 70% of usable farm area, and milk production is almost entirely dependent on local forage production. As a result, current and future changes to the climate pose a major threat to the agricultural sector. Research on extensively managed permanent grasslands in French-speaking Switzerland has shown that plant communities are resistant to drought when the latter occurs early in the growth period. In contrast, if drought occurs later in the season, forage yield losses are pronounced (between 25 and 89%, depending on the site). In these grasslands, intensification of use does not appear to be a viable option for increasing forage yields. Indeed, few options are available to manage drought-related issues. In temporary grasslands, however, there are more drought adaptation strategies, which are primarily based on customising grass community composition. New mixtures that include drought-tolerant species such as tall fescue, lucerne, and sainfoin show promise. When combined with annual or catch crops, a category that includes new species such as sorghum, these mixtures can generally maintain yield levels during drought in temporary grasslands.