The Impact of Different Management Practices on the Ecosystem Services of Swiss Grassland

Whether grasslands are mown or grazed, fertilised or unfertilised – all this affects the ecosystem services of Swiss grasslands. These services benefit both the agricultural sector and society, e.g. in the form of livestock feed or erosion protection.

From forage production to soil protection to attractive landscapes, grassland serves many different functions. All these functions, which benefit us humans, are termed ecosystem services. Researchers from ETH Zurich and Agroscope investigated which services are promoted by which sort of grassland management in the Canton of Solothurn. If many ecosystem services are provided simultaneously, we speak of high grassland multifunctionality.

Over a two-year period, researchers investigated the soils and plant communities of ninety permanent grasslands located on over thirty farms to understand how grassland management influences many different ecosystem services. The grasslands differed in terms of fertilisation (unfertilised extensive ecological focus area (EFA) or fertilisation permitted according to the Principles of Agricultural Crop Fertilisation in Switzerland (GRUD/PRIF)), harvest type (use as meadow or pasture) and management guidelines (organic or conventional according to proof of ecological performance).

Grassland management is key

The three different management approaches were found to have a significant impact on ecosystem services, but to varying extents.

Extensive management (EFAs) resulted in a great number of regulating ecosystem services (e.g. higher plant-species richness, lower risk of nitrogen leaching and phosphorus washout) and cultural services (e.g. aesthetic value), as well as increased multifunctionality. EFAs therefore provide much more than just biodiversity. However, extensive management resulted in a significant reduction in forage quantity and quality. This result shows how strongly management intensity and especially fertilisation affect the different grassland ecosystem services.

Use as pasture or meadow also influenced ecosystem services. Noticeable trade-offs occurred, as some ecosystem services benefited from use as pasture, others from use as a meadow. Forage quality and plant species richness were higher and weed density lower in pastures, which also led to overall slightly higher multifunctionality. The differences between pastures and meadows were presumably due to differences in plant communities, fertilisation intensities and utilisation periods.

Organic management was found to have only a slight positive effect on ecosystem services. Although organic management increased the proportion of symbiotic fungi within the soil fungi and reduced the risk of nitrogen leaching, it failed to influence multifunctionality overall. The reason for this relatively weak impact is probably to be found in the rather small differences between organic and conventional management according to proof of ecological performance.

Complex subject is now accessible

Further information on the study and the measurement of multifunctionality in the Swiss agricultural landscape can be found in Agroscope Science, issue 182. The publication explains step-by-step how ecosystem services and multifunctionality are measured and calculated. It also features an additional example from Swiss arable farming studying the effects of different farming and soil management systems (Wittwer et al. 2021).