## 2 Literature Review
### Agricultural Supply Chain  
The agricultural supply chain contains the whole process of agricultural products from production to sales, how to make a contract to achieve the coordination of the interests of all the subjects in the agricultural supply chain, how to make pricing decisions under the influence of different factors, how to deal with the impact of the New Crown epidemic in the agricultural supply chain, and how to realise the construction of information technology in the agricultural supply chain, which are all urgent problems to be researched in the agricultural supply chain, and therefore, at present, the research on the agricultural supply chain mainly focuses on three aspects. Research on the agricultural supply chain mainly focuses on the three aspects of supply chain coordination, supply chain risk, and agricultural informatisation.  
[PERSON] et al. [4] studied a three-level fresh produce supply chain, analysed the impacts of a flexible quantity contract and relational contract on the supply chain, and found that the former can effectively improve the overall profit and efficiency of the produce supply chain, and the latter can improve the optimal freshness level and the overall profit of the supply chain through incentives. [PERSON] et al. [5] used [PERSON]'s agri-food supply chain as a case study to discuss the supply chain sustainability and cooperation and concluded through empirical analysis that the supply chain sustainability and cooperation can be achieved in the agricultural supply chain. [PERSON] concluded that horizontal contracts should be developed between the three supplier partners, and supply contracts should be developed between suppliers and buyers. [PERSON] et al. [6] analysed the collaboration strategies of producers and retailers in a farmer cooperative-led agri-food supply chain, and found that the introduction of incentives and disincentives under the strategy of strengthened regulation could increase the probability of collaboration and promote supply chain coordination.  
[PERSON] et al. [7] analysed agricultural supply chains under disruptions during the New Crown epidemic, assessed the supply and demand risks, financial risks, etc. faced by different types of firms in the supply chain based on multicriteria decision-making and recommended that firms adopt advanced Industry 4.0 technologies to reduce risks by improving supply chain agility. [PERSON] et al. [8] analysed the impact of the New Crown epidemic on agri-food supply chains, i.e., the New Crown epidemic both promoted the optimisation of risk-coping mechanisms and caused losses for small producers and operators, and based on this, they put forward recommendations to strengthen demand forecasting, develop e-commerce platforms, and use information technology, among other recommendations.  
[PERSON] et al. [9] proposed a practical optimisation model for sustainable closed-loop supply chain (SCLSC) management in the agricultural industry, focusing on the olive crop in Iran. The study emphasised the importance of considering economic, environmental, and social sustainability (the triple bottom line) in supply chain decisions, particularly under uncertainty.  
[PERSON] et al. [10] conducted an evaluation study of agricultural supply chains with the application of IoT technology, noting that IoT technology can optimise supply chain processes, reduce supply chain costs, and improve the quality of agricultural products. Based on the survey data on small farmers in developing countries, [PERSON] et al. [11] proposed a distributed governance approach for the logistics network of the agricultural supply chain which can effectively reduce the information delay between the upstream and downstream of the supply chain and lower the logistics cost.