This study of the institutionalization and professionalization of agricultural chemistry during the second half of the nineteenth century analyses the relationship between chemical theories and social issues, ideas and experience of recycling, the development of fertilizers, and industrialization of agriculture. The study mainly takes a history of science and environmental history perspective with focus on the Swedish case. It does, however, address the international context offering a historical perspective of issues such as the relationship between population and natural resources, the sustainability of society and connections between science, technology and nature. The center of this study consists of an analysis of the work of the following agricultural chemists employed by the Swedish Royal Agricultural Society, enumerated in chronological order: Alexander Müller, Carl Erik Bergstrand, and Lars Fredrik Nilson. Other actors, such as agriculturists, administrators and politicians, were also important in the formation of agricultural chemistry in Sweden. Changes of aims and agricultural chemical ideals during the period of study reflect changes in society and shifting ideologies. During the second half of the nineteenth century a national "agricultural scientific infrastructure" was erected with experimental stations, agricultural schools, local experimental fields and agrarian experts. This network constituted a basis for agricultural science in society and functioned as an important channel for the modernization of agriculture and society. With agricultural chemistry as an empirical point of departure, this thesis also analyzes the transformations of agriculture with the establishment of cultural, economical and physical links between agriculture and the surrounding world. Theories about chemical cycles promoted recycling of nutrition and other materials between the city and the countryside, thereby connecting agriculture to the city. The development of new mineral and nitrogenous fertilizers gradually involved an increased use of inorganic raw materials and energy to manufacture nutrition. This process resulted in the intertwining of agriculture, science, mining, industry and energy production and the creation of an agro- industrial network, which was crucial for the development of agriculture during the twentieth century. In this context, agricultural science legitimized the development toward resource intensive farming methods. / digitalisering@umu