"In the 19th century, the German scientist, Justus von Liebig, formulated the “Law of the Minimum,” which states that if one of the essential plant nutrients is deficient, plant growth will be poor even when all other essential nutrients are abundant".
When I first arrived to this  Justus von Liebig Universitat in 1977 the first thing I noticed near the rly station of Giessen 60 km from Frankfurt was Liebig Museum. Imagine a person becoming Professor in early twenties and getting world fame. He was a chemist by training. The vessel he used to propound his theory of law of minimum was made of several wood pieces and the they were united to different heights . The lowest level of wood piece will determine the level of water that could be filled in the box. He was one to propose to that mineral nutrients are needed by plants and most important are Potassium Nitrogen and Phosphorus while unlike animals plants can obtain carbon from air.
Justus von Liebig Universitat was founded after his name . The Institute of Plant nutrition of Justus Liebig Universitat has produced world famous Professors which included Professor Dr Mengel, Professor Dr Hoffner, Professor Dr Neumann, Professor Dr Muhling  and at present Professor Dr Sven Schubert . Students across the globe come here for study and training. Its the pioneer institute of learning about plant plant nutrition, stress etc. I am lucky to have a chance to study here with support from Alexander von Humboldt Fellowship with Professor Dr Neumann and now Professor Dr Sven Schubert  and a dedicated team of distinguished scientists like Professor Steffens and fellow workers and  research students  from across the globe. The Justus von Liebig Museum has beutifully exposed his ideas and even practical demonstrations take place of his ideas. The law of the minimum was only one of the discoveries of Justus von Liebig on whose name the University is founded.