Edwin Scheller, a German agronomist, is known for his work on plant nutrition, particularly for highlighting the "active mobilization of nutrients by the plant". Supported by solid scientific results, especially studies on potassium, phosphorus, and amino acids, the author's thesis challenges the classical theory of plant nutrition. He demonstrates that the plant is capable, from a certain stage of its development and under correct agronomic conditions, of releasing the nutrients it needs from the minerals in the soil.
In addition to its scientific aspect, this work offers insights into the history of biodynamic and organic farming, and their development in relation to the scientific context of the time. It provides an understanding of some of Steiner's contributions, particularly his approach to fertility, by connecting them with the agricultural theories of the era.
This unfinished work, due to the premature death of its author, hence its name "A Fragment", is considered valuable for many professionals.