Context. There is a limited understanding of how land-use intensity influences the relationship between plant diversity and the ecosystem function of aboveground biomass production in semi-natural grasslands at the field and farm scale. However, these spatial scales are critical to be addressed since management practices are applied at larger spatial scales than biophysical characteristics are measured. Objectives. We aim to (1) examine the direct and indirect effects of land-use intensity on the spatial variability of biomass production, focusing on the role of plant species richness and its spatial variability at the field scale. We further aim to (2) compare the strength of the biodiversity-ecosystem functioning (BEF) relationship across spatial scales under different land-use intensities. Methods. Going beyond the plot scale, we investigate the field and farm scale in two German regions for the years 2020 and 2021. Statistical analyses are based on prediction maps for species richness, biomass and land-use intensity, upscaled using Sentinel-2 satellite imagery, as well as on spectral dissimilarity (Rao\'s Q) to account for environmental heterogeneity. Results. High land-use intensity directly reduced species richness and its spatial variability, which acted as mediators, however, not as buffers for the spatial variability of biomass production at the field scale. The BEF relationship strengthened slightly with spatial scale at low land-use intensity, but is weakened under medium or even reversed under high intensity. Conclusions. Our study provides new insights into how land-use intensity shapes the BEF relationship at spatial scales relevant for management, addressing spatial mismatches in complex social-ecological systems.