We further find that the Standardized Precipitation–Evapotranspiration Index (SPEI), currently used operationally as a proxy for agricultural droughts in Belgium, underestimates the persistence of root-zone droughts because it does not explicitly account for land-surface memory. Thus, by including soil moisture monitoring in drought assessment, residual stresses on agriculture and subsurface water, which can persist long after meteorological conditions have normalized, can still be detected. This gives decision-makers a more realistic understanding of droughts and how to respond proportionately.