a German chemist who made major contributions to agricultural and biological chemistry, and was considered the founder of organic chemistry. As a professor at the University of Giessen, he devised the modern laboratory-oriented teaching method, and for such innovations, he is regarded one of the greatest chemistry teachers of all time. He has been described as the "father of the fertilizer industry" for his emphasis on nitrogen and trace minerals as essential plant nutrients, and his formulation of the Law of the Minimum which described how plant growth relied on the scarcest nutrient resource (limiting factor), rather than the total amount of resources available.
