Impact of Climate Change on Phenology, Productivity, and Water Use Efficiency of Major Cereal Crops in Pakistan
https://doi.org/10.5281/zenodo.19121578
Keywords:
Climate Change, Pakistan, Cereal Crops, Phenology, Productivity, Water-Use Efficiency, Wheat, Rice, Maize, Heat Stress, Drought, Co₂ Elevation, Indus Basin, Adaptation Strategies, Food SecurityAbstract
Pakistan, ranked among the top ten climate-vulnerable nations, faces severe socioeconomic threats from rising temperatures (0.5–1.0 °C increase since 1960), erratic precipitation, and extreme events, profoundly impacting its agriculture sector (24% GDP contribution, 37.4% employment). This review synthesizes the effects on major cereals wheat, rice, and maize focusing on phenological shifts (e.g., shortened growth cycles by 5–15 days), productivity declines (projected 10–20% by 2050), and altered water-use efficiency (WUE) amid water scarcity affecting 80% of arable land. Elevated CO₂ enhances photosynthesis but is offset by heat stress reducing grain filling; drought exacerbates WUE reductions (10–30%) via stomatal closure and biomass loss. Regional variations highlight Indus Basin vulnerabilities, with glacial melt disrupting irrigation. Adaptation strategies climate-smart varieties, precision irrigation, and diversified cropping offer mitigation, potentially stabilizing yields and WUE. Projections indicate 15–25% GDP losses without intervention, underscoring the need for integrated policies to bolster rural resilience and food security in this climate hotspot.
