Guomai mintian 國脈民天 "[Food is] the artery of the state and the people's heaven" is a general book on agriculture written during the late Ming period 明 (1368-1644) by Geng Yinlou 耿蔭樓 (d. 1638), courtesy name Xuanji 旋極, from Lingshou 靈壽 in today's Hebei province. He obtained the jinshi degree in 1625 and obtained an office in the local administration. Geng was killed during the Manchu invasion of the northeast.
The short book is divided into seven chapters explaining the methods of compartment fields (Qutian 區田), the "close [and rotating use]" of fields (Qintian 親田), planting (Yangzhong 養種), drying seeds (Shaizhong 曬種), the use of manure (Chufen 蓄糞), methods against draught (Zhihan 治旱), and preparations against natural disasters (Beihuang 備荒). There is also an appendix on irrigation (Gaitianfa 溉田法) It seems that Geng himself was very familiar with farming.
The text is included with the title Geng Songyang Xiansheng zhongtian fa 耿嵩陽先生種田法 in Pan Zengyi's 潘曾沂 (1792-1852) series Fengyu zhuangben shu 豐豫莊本書. Qin Jukui's 秦聚奎 (1553年－1627) print of the text includes an illustration on one area of compartment fields (Quqian yi mu tu 區田一畝圖). The book is also found in Zhao Mengling's 趙夢齡 collection Quzhong wu zhong 區種五種 (1878) and Wang Yuhu's 王毓瑚 (1907-1980) Quzhong shi zhong 區種十種.