Beigenglu 北耕錄, also called Nongshu caogao 農書草稿, was an agricultural treatise written during the late Ming-period 明 (1368-1644) by Xu Guangqi 徐光啟 (1562-1633), who is famous for his book Nongzheng quanshu 農政全書.
The original text of the Beigenglu is already lost, and only a draft survives which was published in 1962 by the Zhonghua Shuju Press 中華書局. It is also included in the 1982 collection of Xu's writings and translations, Xu Guangqi zhuyi ji 徐光啟著譯集, published by the Shanghai Guji Press 上海古籍出版社.
The Beigenglu focuses on various methods of producing fertilizers, but also comments on the process of ink and brush making, quicksilver and sulphur, and camel breeding. The text is to a great extent based on older sources like Wu Yunjiang's 吳雲將 prescription for manure (fendan 糞丹) or Yuan Liaofan's 袁了凡 method, but also comes from the author’s personal experience in the fields. Wu’s "dung pill" makes use of human excrements (dafen 大糞), grains of hemp (masan 麻糝), black beans (heidou 黑豆), pigeon dung (gefen 鴿糞), animal carcasses, internal organs, hair and blood, "black alum" (heifen 黑礬, ferrous sulfate), orpiment (? pixin 砒信), and sulfur (liuhuang 硫磺). These ingredients are mixed in a jar which is then tightly sealed and can be reopened after a while. One dou 斗 (see weights and measures) of this fertilizer has the vitalizing power of ten dan 石 of human excrements, e.g. hundred times efficient.