How productive is grassland in Switzerland? An approach to spatially differentiate yield estimation in Swiss grassland

This study presents spatially explicit grassland yields based on the LPIS (Land Parcel Identification System) production levels for Switzerland in 2023. The published land use data were part of the project “Maps for site-adapted arable land and grassland production”, supported by the Swiss Federal Office for Agriculture. Herein we developed a model that provides a spatially differentiated representation of grass yields to identify regional yield patterns. The focus was on grassland areas (e.g. meadows, pastures, and ley) located in valley, hill, and mountain zones, excluding summer pastures. We conducted a Swiss-wide assessment using geodata models in ArcGIS Pro 3.2.2 (Esri, 2022), which were based on the Swiss national agricultural inventory data (equivalent to the European LPIS data) at the farm level. Therefore, we designed a multi-stage modeling framework that combined high-resolution geospatial data with parameters derived from literature. Using altitude-dependent yield values, average grassland yields (dt DM ha-1a-1) were first calculated based on the principles of fertilisation of agricultural crops in Switzerland (PRIF). To fully account for grassland yields, we considered dry matter losses during storage of grass forage. In a subsequent processing step, we developed a two-criteria assessment and grassland yields were adjusted to account for drought and exposure-related radiation conditions. For spatial consistency and compatibility with other geodata, all datasets were resampled and standardized to a uniform 25 m grid and projected into the Swiss national projection system (CH1903+_LV95).