Main Factors Affecting Post-Harvest Grain Loss during the Sales Process: A Survey in Nine Provinces of China
Ensuring food security has always been a top priority of the Chinese government. However, China's grain supply is facing challenges due to limited resources for grain production and the growth of domestic grain consumption. Reducing post-harvest grain loss represents one of the most realistic and effective ways to ensure grain security in China. In view of the importance of grain sales in the post-harvest period, we conducted a survey, interviewing 1890 grain sellers across 54 regions in 9
... nces of China, to investigate the factors affecting post-harvest grain loss during sales. The results of the survey show that grain storage conditions have the greatest impact on post-harvest grain loss, followed by transportation. Display and sales have the least impact on grain loss. The Tobit regression model was used to analyze the main factors affecting post-harvest grain loss during sales. The findings suggest that the seller's education level, years of working as a seller, the conditions of grain storage, and the supply and management level of public facilities in the market were negatively correlated with grain loss in the sales process, whereas the seller's age, the separation of sales shops and storage warehouses, and the fall season were positively correlated with grain loss. Policy implications are also provided for potential future policy decisions. fresh water, fertilizers, and other resources used in grain production, which does not go along with sustainable development. Therefore, it is very important to reduce post-harvest grain loss to ensure a sufficient supply of grains and to make utilization of the agricultural production resources sustainable. Post-harvest loss was defined by Boxall (1986) as loss that occurs when the grain is taken from the site of growth or production to the point where it is prepared for consumption  . Since then, scholars from developing and developed countries, as well as different international organizations, have conducted pilot studies on this concept across different countries or regions based on local situations. For example, Aulakh and Regmi (2013) referred to post-harvest food loss as the inevitable loss of grain caused by objective factors, such as the lack of infrastructure, the lack of management and technology, and outdated equipment . Song et al. (2015) defined the concept of post-harvest grain loss as the sum of all tangible grain losses during the processes of harvesting, transportation, drying, and storage . Based on the existing literature and the situation in China, Wu et al. (2017) pointed out that post-harvest grain loss should refer to the decrease in quantity and quality of edible grain in the supply chain caused by factors such as natural conditions, infrastructure, technological equipment, management decisions, and practitioners' individual characteristics . In fact, the post-harvest period involves many steps. It refers to the entire supply chain system, from harvesting to consumption: harvesting, transportation, drying, storage, processing, sales, and consumption  . Post-harvest grain loss can occur between these steps, and the extent and causes of grain loss vary depending on the nature of the specific post-harvest steps and the type of grain. In previous studies, most researchers put their focus on specific steps in the post-harvest grain loss process     , such as harvesting, transportation, storage, or consumption. It is rare to investigate grain loss during sales, especially in developing countries (and regions), including China. The sales step, as the final step in the grain production-consumption process, plays an important role in reducing post-harvest grain loss. Accordingly, China has promulgated relevant policies to promote the structural transformation of grain sellers. In particular, local governments are required to adopt preferential policies to support knowledge-based, technology-based, and scale-based sellers to reduce grain loss at the sales stage. Understanding the main factors affecting post-harvest grain loss during the sales process in China will help with better design of intervention steps to reduce grain loss and promotion of sustainable development of the grain supply. Therefore, the objective of this study was to investigate the main factors affecting post-harvest grain loss at the sales stage, by applying the Tobit regression model to analyze the data obtained from valid questionnaires of 1662 grain sellers across 54 regions in 9 provinces of China. It should be pointed out that based on China's actual situations and previous research findings, grain loss at the sales stage is defined as "the amount of grains that are reduced before reaching consumers during the sales process due to limited operating conditions and the lack of management capacity at the sales stage," and the sales stage is divided into subcategories: transportation, storage, and display and sales. In our study, we examined post-harvest grain loss involving the sellers and channels specified in Figure 1 . The different scales of grain sellers in China include wholesale markets, farmers' markets, supermarkets, retail stores, and grain and oil specialty stores. The grains for sale that were surveyed included rice, wheat, maize, soybean, peanut, rapeseed, and others.