Divergent responses of crop yields to meteorological and agricultural drought characteristics

Understanding the evolution of drought event characteristics and their impact on crop yields is crucial for climate adaptation and food security. Although traditional research has focused predominantly on establishing correlations between drought indices and crop yields, the understanding of how crops respond to drought characteristics remains less explored. Here, we applied the Standardized Precipitation Evapotranspiration Index and the Standardized Soil Moisture Index to characterize meteorological drought (MD) and agricultural drought (AD), respectively, during the growing seasons of winter wheat and maize from 1973 to 2023 in China. Drought events were identified using the multi-threshold run theory, and their frequency, intensity, severity and duration were quantified. Partial wavelet coherence was then employed to assess the responsiveness of the detrended crop yields to various characteristics of drought events. The results showed that, from 1973 to 2023, the proportion of stations affected by MD during the growing season increased (winter wheat: from 28.9% to 31.8%; maize: from 30.5% to 34.8%), whereas AD exhibited fluctuating trends. MD events occurred more frequently and with greater intensity, while AD events were characterized by longer duration and higher severity. Crop responses differed markedly: winter wheat showed the strongest response to AD intensity, with a percent area of significant coherence (PASC) of 28%, whereas maize was most sensitive to MD frequency (PASC: 28%). These findings highlight the need for crop-specific drought adaptation strategies: improved soil moisture management for winter wheat and enhanced monitoring of meteorological drought for maize.