【正文】
the same time, products from the market to close and only a single farm, it also makes the chain in Most of the main trading agricultural producers, their direct trading in the market, and little w contact between producers and consumers, middlemen, so growers sell directly to consumers food and agricultural products. In developing countries, especially near urban areas, the supply of vegetables, generally using this type of supply chain. type of food supply chain. This type of food supply chains are generally applicable to food and agricultural production and sales of land to the far distance, consumer demand quite different situation. As perishable agricultural products, agricultural producers can not sell their products directly, through intermediaries to provide the necessary services, such as thirdparty logistics, agricultural processors and wholesalers provide appropriate services. This type of supply chain, upstream gathered more producers, and in the middle part of a better understanding of the origin of production, but also in the sales channels to occupy a certain advantage, but fewer vendors. Therefore, Tfood supply chain and many growers, brokers and sellers and less downstream and concentrated, showing the shape of the supply chain for the Ttype. And dumbbellshaped pared to the food supply chain, which chain is longer, the sales performance of food and agricultural products and valueadded services for the indirect nature. This type of food supply chains more mon in China, China’s agriculture industry in less developed regions, due to lack of upstream farmers to connect one end, other end of the link sales market, specializing in the processing of agricultural products among leading enterprises and the corresponding part of agricultural production often out of line with market demand. Therefore, Tmiddle part of the food supply chain as a low level of absence and logistics operation, prone to upstream farmers and downstream production of agricultural products sold blindly difficult phenomenon. 3. symmetric food supply chain. With the emergence of new sales formats, distribution channels are increasingly largescale professional market w and supermarket monopoly, the traditional sales of agricultural products and food forms have been replaced by supermarkets, and this trend is more and more obvious, and because of its technological level of agricultural products production also tends to intensive management by a few growers. Ahe by the Royal Thai supermarket fresh food supply chain management survey found that 50% of Bangkok’s food and agricultural products in large supermarkets (such as 711, Royal Ahe, Carrefour, Sainsburry and TESCO) sold of. These large supermarkets in order to meet the market for agricultural products, quality consistency and supply stability requirements, the supplier of a rigorous screening. Therefore, the implementation of the Royal Ahe supermarket fresh food supply chain management, will be vendors from the original 250 was reduced to about 60, so that the logistics system more efficient and concise. With the upper reaches of the sharp drop in the number of suppliers of agricultural products and the continuous expansion of the supermarket chain, this food supply chain, upstream suppliers and downstream number of supermarket chains showed symmetrical growth trend. Logistics development in developed and more mature cities, this has been expressed in the food supply chain, centralized purchasing, reduce nonuniform flow distribution and valueadded logistics sectors, in order to achieve cost savings of lean logistics strategy. 4. mixed food supply chain. With consumer demand for food and agricultural products market diversification, the proportion of food and agricultural processing has gradually improved. According to the statistics that the United States in 2021 raw and processed vegetables for 15% and 85%。 the third stage of supply chain integration management phase, the study extends further upstrea