The agricultural and hydraulic sciences and technologies of the Han Dynasty were also incomparable in the world at that time. First, iron farming tools and ox-farming techniques were widely employed throughout the Han empire, and intensive farming techniques such as the “daitianfa” and the “qutianfa” were promoted by agricultural officials so that the crop output per mu improved substantially. Second, the imperial government followed the agriculture-first idea and stressed agriculture repeatedly as the stem-trade, and many agricultural books were written at that time, e.g. the Fan ShengzhiFan Shengzhi(氾胜之) Shu and the Simin Yueling. Third, countless large water control and irrigation projects were built in the Han Dynasty, including renowned projects such as the Cao Canal and the Bai Canal, especially Emperor Wu’s massive Huzi project to treat the Yellow River by stuffing the breach at the mouth of the Huzi River. These projects demonstrated the advanced hydraulic sciences and techniques of that time, which were included in works such as Yugong, Hequ Shu and Gouxu Zhi.