Chemical analyses play an important role in agriculture, supporting technologies at all stages of agro-industrial chains, such as grains, forests, pulp and paper, waste, and agricultural residues, among other sources of agricultural products. Furthermore, chemical analyses give the knowledge of chemical composition and the presence or absence of contaminants in food and animal feed, and the soil and water quality and their pollution levels. A set of relevant analytical techniques is discussed in accordance with their application in agriculture.