Global cotton yield trends and the driving factors: insights from a spatiotemporal analysis

Cotton is one of the most economically valuable fiber crops worldwide. Understanding the factors influencing its yield under climate change is crucial for managing climate risks, ensuring a stable textile supply, and promoting sustainable development globally and regionally. This study systematically analyzed the annual yield trends in 82 cotton-producing countries from 1992 to 2021. It investigated the driving factors of cotton yield using eight key indicators, including resource inputs, management practices, and climatic variables. Results show that global cotton yields increased by 27 t km−2 annually, with higher growth in high-income and upper-middle-income countries, the latter achieving yields twice the global average. In contrast, lower-middle-income countries experienced slower growth, while low-income countries faced slight declines. Arid regions maintained the highest yields, with significant improvements across tropical, temperate, and arid zones. Using a varying coefficient spatiotemporal regression (geographically and temporally weighted regression (GTWR)), the study further revealed significant regional variations in the driving factors of cotton yield. Globally, cotton-planted areas and labor inputs negatively impacted yields, as larger areas can lead to insufficient management and high labor density indicates a lack of mechanization. In contrast, fertilizer application and sunlight improved yields, while rising temperatures suppressed them. Regional differences were also observed: mechanization enhanced yields in high-income countries, increased land allocation to cotton improved yields in tropical regions, and fertilizer use drove yield growth in low-income regions. This study highlights the spatial and temporal heterogeneity of global cotton production and offers scientific insights to inform region-specific agricultural management policies and sustainable development strategies.