Benito-Verdugo et al. (2026) Impact of flash droughts on cereal crops under Mediterranean conditions

Identification

• Journal: Spanish Journal of Agricultural Research
• Year: 2026
• Authors: Pilar Benito-Verdugo, Ángel González‐Zamora, José Martínez-Fernández
• DOI: 10.5424/sjar/2025234-21655

Research Groups

• Instituto de Investigación en Agrobiotecnología (CIALE), University of Salamanca, Spain.

Short Summary

This study characterizes flash droughts (FD) in Mediterranean rainfed cereal regions from 2000 to 2023, demonstrating that these rapid-onset events significantly reduce crop yields by up to 33% and accelerate phenological development. The research highlights that cereals respond to soil moisture deficits within five days, particularly during critical growth stages in spring.

Objective

• To identify and characterize flash droughts in Mediterranean rainfed cereal systems and quantify their specific impacts on gross primary productivity (GPP), grain yield, and phenological timing.

Study Configuration

• Spatial Scale: Regional (Major cereal-producing areas of Spain [Castilla y León, Castilla-La Mancha], Portugal [Alentejo], France [Occitanie], and Italy [Puglia]).
• Temporal Scale: 2000–2023 (Focusing on the agricultural year from October to July).

Methodology and Data

• Models used: Nonparametric Gringorten plot position approach for soil moisture percentiles; Flash Drought Intensity Index (FDI); Piecewise linear regression for phenological stage detection; Cubic spline interpolation for NDVI smoothing.
• Data sources:
  • Soil Moisture: ERA5-Land reanalysis (root-zone 0–100 cm).
  • Vegetation/Productivity: MODIS (GPP: MOD17A2HGF/MYD17A2HGF; NDVI: MOD13A1/MYD13A1).
  • Yield: National statistics from MAPA (Spain), INE (Portugal), AGRESTE (France), and Istat (Italy).
  • Land Cover/Masking: ESA CCI Land Cover map and FAO Digital Global Map of Irrigation Areas.

Main Results

• FD Characteristics: Most regions experienced 7–12 FD events over the 23-year period, with a predominant duration of 50–60 days (10–12 pentads).
• Critical Timing: The highest frequency and severity of FD occurred between April and June, coinciding with the reproductive and grain-filling phases of wheat and barley.
• Ecological Sensitivity: Cereals showed an extremely rapid response to FD, with over 75% of events resulting in negative GPP anomalies within the first 5 days (1 pentad).
• Yield Impact: Flash droughts caused substantial yield losses, peaking at 33% for both wheat and barley in Castilla-La Mancha. Significant negative correlations were found between FD severity and yield in the Spanish regions.
• Phenological Shift: FD events induced a slight advancement in all developmental stages, with the greatest average shifts observed in stem extension (3.6 days) and ripening (3 days).

Contributions

• Provides one of the first integrated analyses of FD impacts specifically on rainfed cereal crops (wheat and barley) rather than natural vegetation.
• Quantifies the "rapid-response" threshold for Mediterranean cereals, showing that physiological stress manifests within a single pentad (5 days) of FD onset.
• Links FD events to specific phenological accelerations, offering new insights into crop resilience and adaptation strategies under climate change scenarios.

Funding

• Spanish Ministry of Science, Innovation and Universities (MCIN/AEI/10.13039/501100011033/ Project PID2020-114623RB-C33).
• Castilla y León Government (Projects SA112P20 and CLU-2018-04).
• European Regional Development Fund (ERDF).
• Spanish Ministry of Science, Innovation and Universities (Predoctoral grant FPU20/00592).

Citation

@article{BenitoVerdugo2026Impact,
  author = {Benito-Verdugo, Pilar and González‐Zamora, Ángel and Martínez-Fernández, José},
  title = {Impact of flash droughts on cereal crops under Mediterranean conditions},
  journal = {Spanish Journal of Agricultural Research},
  year = {2026},
  doi = {10.5424/sjar/2025234-21655},
  url = {https://doi.org/10.5424/sjar/2025234-21655}
}

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