Although many Chinese farming manuals (nongshu 農書) contain detailed information on proper methods for tilling the soil, such as plowing, harrowing, or fertilizing, they provide little detailed explanations on why scholars regarded these methods as effective; instead, they often just argue for a “balanced soil” (和土). One exception, though, is the Nongshuo 農說 (Explanations on Agriculture) by the Ming dynasty scholar-official Ma Yilong 馬一龍 (ca. 1499–1570), an agricultural writing that has been largely neglected so far and which will be the focus of this project. According to the agricultural historian Wang Yuhu 王毓瑚 (1907–1980), the theoretical content of the Nongshuo is something rarely seen in ancient agricultural writings, and thus it deserves closer attention. In this project, I explore the terminology and basic concepts of nature that late Ming agronomists like Ma Yilong used to explain soil. Many of these concepts were borrowed from other fields of knowledge like medicine, astronomy, or alchemy, and therefore farming manuals are a valuable source to study the developments of sciences in China. This project shows that the unique contents of the Nongshuo provide a deeper understanding of early modern scholarly conceptions of agricultural practices in general and of soil in particular.