Use Manure like Medicine: The Medical Influence on Late Ming Agronomists’ Ideas on Soil and Fertilizers (Jörg Henning Hüsemann)
In the 19th century, many innovative techniques were introduced to improve Western agriculture. Among these, the so-called “fertilizer revolution” was an important step in increasing the farmers’ yields. Particularly after German chemist Justus von Liebig (1803–1873) had proposed his ideas on agricultural chemistry, agriculture developed from empirical to laboratory agriculture. Liebig proved that plants consume minerals contained in the soil during their growth and that this loss must be compensated by fertilization. He was also interested in Chinese agriculture and wrote in one of his articles that comparing Chinese to Western agriculture was like comparing a father to a child. In his eyes, Chinese agriculture was purely empirical, as he believed that Chinese agronomists had not developed any scientific or theoretical ideas – a common opinion in the 19th century, but a false one nonetheless. In fact, based on their own knowledge and perceptions, Chinese agronomists had early explained agriculture in terms of various concepts of nature. A rich case for a better understanding of the agronomists’ theoretical considerations of agriculture is their descriptions of soil and fertilization. Using Ma Yilong’s Nong shuo and Yuan Huang’s Baodi quannong shu as examples, I will discuss the basis on which the agronomists of the late Ming period developed their understanding of soil and fertilization. In my presentation, I will argue that Ma Yilong and Yuan Huang were both influenced by medical concepts. Therefore, their accounts were not only based on empirical, but also contained a considerable amount of theoretical knowledge. Their agricultural manuals are therefore good examples of how Chinese agronomy developed from empirical to scientific agronomy during the Ming and Qing dynasties.
The Earthly Qi and Manure as Medicine: Constructing Theories of Fertilization in Traditional China (Du Xinhao)
Prior to the modern science of fertiliser, it was widely recognised that there was a certain “energy” latent in the soil by which crops obtained their yields and that farmers had to return the “energy” taken from the soil by fertilising it regularly in order to maintain the balance of “energy” in the soil. Early modern scientists have offered various explanations for the presence of this “energy” in the soil, which has been described as salt, water, nitrate and humus. In 1840, J. von Liebig proposed the theory of mineral nutrition of plants, which confirmed that crops survive by absorbing inorganic nutrients from the soil, thus ending a long-standing debate on the subject. In traditional China, the learned class constructed a set of theories on fertilisation based on their own perception of nature and their own knowledge structure, systematically elaborating on issues such as why the land lacks fertility, what substances can replenish it, what principles should be followed in fertilisation and how fertilisers work in the soil and plant body. Examining these theories not only provides an overview of how soil and fertilization were understood, but also a glimpse of the influence of traditional Chinese medicine on agronomy.
在近代肥料科学诞生之前，人们已经普遍意识到土壤里潜伏着某种“能量”，作物藉由它获得产量，农民要经常以施肥的方式将作物从土壤中带走的“能量”归还给它，才能维持土壤中的“能量”平衡。近代以来，科学家们对土壤中存在的这种“能量”给出了多种解释，它先后被阐述为盐、水、硝石与腐殖质等物质，直到1840年，李比希（J. von Liebig）提出“矿质营养学说”，确认作物是依靠吸收土壤中无机养分而生存的，从而结束了长期以来围绕此问题的争论。其实，早在中国古代，士人阶层就依照其自身所认知的世界图景及知识结构构建了他们的一整套施肥理论，对土地缘何缺失肥力，何种物质可以补充地力，施肥应该遵循哪些原则以及肥料如何在土壤与植物体中发挥效用等诸多问题都进行过系统性阐述，从中可以了解中国古代施肥理论的生成与演化模式，亦可窥见中国传统医学对农学影响之一斑。