Emphasizing grain reserves is an excellent historical tradition in China. Data shows that China's main grain reserves have exceeded 50% of global inventory, making it the world's largest grain storage country. The Chinese people's rice bowl is firmly in their hands. Food is the top priority for the people, and food security is the "greatest of the country". So how did the ancients manage food storage and supply security, and what historical experiences are worth learning from? The picture shows Fengtu Yicang located in Dali County, Shaanxi Province. It was built in the eighth year of the Guangxu reign of the Qing Dynasty (1882) and covers an area of 11039 square meters. The architectural layout is a city within the city, divided into an inner city and an outer city. The outer city faces east and west, with rammed earth to build the city, which is the first line of defense for the Yicang defense. The inner city is constructed in the form of a building that combines warehouses and walls, and has dual functions of defense and warehousing. Cixi was once granted the title of "the first warehouse in the world" by the emperor. (Image source: CCTV) The origin of grain storage and famine preparedness: Early ancient ancestors attached great importance to grain reserves. At the Cishan Cultural Site in Wu'an, Hebei (over 8000 years ago), archaeologists excavated 189 "granaries" that could store at least 50000 kilograms of millet. Under the production conditions at that time, the scale of such grain storage was astonishing. In the Chizhong Temple terrace of the Liangzhu Cultural Site, which dates back more than 5000 years, archaeologists have discovered a charred rice pile with an area of over 10000 square meters, indicating a huge grain storage capacity in the city. The oracle bone inscriptions contain records of sending officials to inspect granaries, indicating that the Shang Dynasty had a relatively sound grain reserve system. According to the Book of Rites of Zhou, administrative institutions at different levels of the Western Zhou Dynasty had reserve warehouses, including grain reserves. The official in charge of reserves is called "Yiren", whose function is to manage the kingdom's reserves (referring to the reserves of food and other assets), and use them to bestow favor on the people; Responsible for the accumulation of resources in the village, used to relieve the hungry and sleepy among the villagers; Responsible for the sacrifice of gatekeepers (national gates and gates), used to raise the families of victims of the country; Responsible for the accumulation of resources in the suburbs, used to provide guests entering and exiting the royal capital; Responsible for the deposit of Yebi (within 300 miles of the capital), used to supply passengers traveling between them; Take charge of the county capital's reserves to prepare for disasters and famine. Today, the grain reserve regulation system we are talking about is generally believed to have originated from the "d í" (meaning to buy grain) law implemented by Li Xi, the Duke of Wei during the Warring States period. This system involves the government using fiscal power and pricing measures to regulate grain supply and stabilize grain prices. The "Ping Buying Law" divides the good annual yield into three levels: upper, middle, and lower. The bad annual yield is also divided into three levels: upper, middle, and lower. The state purchases or sells a corresponding amount of grain according to the annual yield. For example, in a bad harvest year, the grain increment purchased in the Dafengshou (Salad of assorted fresh vegetables) year will be sold to balance the supply and demand of grain in the market. The result of purchasing goods is that "although facing famine, floods, and droughts, buying goods is not expensive but the people are not scattered, and taking surplus to make up for the shortage. When we act in the Wei state, the country will be prosperous and strong. The Ping Buying Law has restricted illegal merchants' speculative activities in grain, effectively preventing farmers from going bankrupt and the exile of the poor, and maintaining the normal economic order of the country. After the Qin and Han dynasties, the system of grain reserves and adjustments was quite complex, but there were generally no two types: the "Changping" established by the state