Grain supply–demand in countries along the "Belt and Road" from 1993 to 2021: spatiotemporal evolution, match, security and driving mechanism.

Introduction: The grain supply-demand balance is a long-standing concern for many countries and is essential to guaranteeing social stability, maintaining economic development and ensuring national grain security. Methods: Based on the data of 65 countries along the "Belt and Road" (B&R) from 1993 to 2021, this paper analyzed the spatiotemporal evolution, the matching relationship, regional grain security situation and driving factors of grain supply-demand by measuring and classifying the grain self-sufficiency rate using methods such as geostatistical analysis and the GTWR model. Results: The results indicated the following: (1) The B&R region was still at the primary stage of "food-based and feed-supplemented". Grain supply and demand in the B&R region showed a steady upward trend, with grain yield contributing more to grain supply than sown area. (2) Overall, the B&R region has been largely self-sufficient since 2007, with grain supply meeting demand, but the level of grain self-sufficiency varied considerably between countries. (3) More than 58% of the countries were in grain insecurity, concentrated in West Asia-Middle East and South-East Asia. The gravity center of both grain supply and demand was near East Asia. (4) In terms of matching supply-demand, most countries fell into the category of high supply-high demand and low supply-low demand, with basically the same level of grain supply and demand. (5) Grain yield had the largest positive impact on grain supply-demand, GDP had the largest negative impact, and temperature change and precipitation change had a relatively small effect. The effects of fertilizer use, grain yield, and GDP on grain supply-demand fluctuated greatly over time. Discussion: These findings can provide a scientific basis for the country to formulate policies for a sustainable grain supply-demand system. [ABSTRACT FROM AUTHOR]