2. The so-called study field refers to the fields used by academies and state-owned schools, which is the economic pillar of school education in feudal society in China. The system of setting up schools to support learning was founded in the Song Dynasty, and it continued to the last stop of feudal society in China, namely the Qing Dynasty.

3. Fuzhou School in Song Dynasty was granted land by the imperial court for the first time in November of the first year of Ganxing (1022). Sun _, who rebelled against imperial academy, asked the court to grant Yanzhou Jiaotian 10 hectares, and the court granted him "learning food". Since then, various places have followed suit. This move is considered to be the beginning of the study of farmland system in Song Dynasty.