A research review of global grain harvest losses

Abstract

[Objective] Due to differences in economic and technological development levels, postharvest losses (PHL) in different stages of the grain value chain varies greatly across the world. Identifying the extent of PHL and the influencing factors globally can provide crucial information for food loss reduction in China. [Methods] This study focused on grain harvest losses and selected 98 relevant publications according to the Preferred Reporting Items for Systematic Reviews and Meta- Analyses (PRISMA) guidelines. We constructed a database of international publications on grain PHL, including academic papers and research reports on four types of grain crops (rice, corn, wheat, and soybean). [Results] The results show that the attention to PHL of grains is increasing globally in the past decades, but focused mainly on the developing countries and regions in Asia, Africa, and South America. On average, the post-harvest grain losses at the global level are 6.651%, but heterogeneity of grain harvest losses existed in different countries due to factors such as climate, harvest methods, technical conditions, and labor quality. Although the introduction of mechanized harvesting has improved the production efficiency, the impacts of nonstandard operation and the use of third- party contractor services on harvest losses cannot be ignored. The lack of research on combine harvester performance also limited the application of mechanization technologies. Besides, equipment and facility shortages in the stages of drying and storage also led to increased PHL. [Conclusion] Therefore, we suggest paying more attention to the research of mechanical harvest technologies and operation methods, as well as renewing and revising technical standards continuously and improve the infrastructure environment for harvesting according to domestic economic conditions and industrial development. This study also provided detailed information and policy recommendations for PHL reduction in China.