as the Queue hairstyle and pay taxes to the Qing government. But most of the Korean emigrants considered adopting Manchu's addressing codes a discriminatory policy of assimilation. By 1910, the number of Korean migrants in China reached about 260,000, with around 100,000 of them living in the current-day Yanbian Korean Autonomous Prefecture. Development of paddy fields in Northeast China The development of paddy fields in Northeast China during the modern era was related to rice cultivation by Korean emigrants. Korean emigrants attempted to cultivate rice in the Hun River valley as early as 1848. The experiment by Korean farmers in the Dandong region was successful in 1861. In 1875, Korean farmers also succeeded in cultivating rice in the wetland of Huanren region in Liaoning province. The cultivation of rice in Yanbian region began in 1877. The growth of paddy fields brings the further development of irrigation projects in Northeast China by Korean farmers, who built numerous watering canals to irrigate paddy fields. In June 1906, 14 Korean farmers built the earliest irrigation system in Yanbian. The total length of canals built exceeded 1.3 kilometer, irrigating 33 hectare of paddy fields. On 3 March 1914, the newly established Republic of China issued a decree aimed to encourage land development in Northeastern China. In the same year, the water bureau of the Mukden province began to recruit Korean emigrants to use the water from Hun River to develop paddy fields near Mukden. In 1916, the local government of Jilin Province submitted a paddy field farming specifications document of a Korean immigrant farmer to the central Agriculture and Business Administration. After receiving the administration's approval, Jinlin Province started to promote rice production. Han Chinese farmer began to hire Korean emigrants to learn how to grow rice. In 1917, Korean farmers in Muling solved the problem of how to grow rice in regions with short frost-free period. Rice farming thereafter quickly expanded to the further north region of Mudan River, Muling River and Mayi River basins. Between 1921 and 1928, the total areas of paddy fields in Northeast China increased from 48,000 hectare to 125,000 hectares, more than 80% of these rice fields was developed or cultivated by Korean farmers. In 1933, Korean farmers succeeded in growing rice in Aihui and Xunke area along Amur River, breaking the world record of growing rice north of the 50th parallel north. In 1934, Korean population accounted