Nitrogênio, potássio e cálcio em Steiner (2007)
The bio-dynamic school of thought and a chemically-minded agricultural thinking confronted one another from opposite points of the compass at the time the agricultural course was held. The latter school is based essentially on the views of Justus von Liebig. It attributes the fact that plants take up substances from the soil solely to the so-called “nutrient-need” of the plant. The one-sided chemical fertiliser theory that thinks of plant needs in terms of nitrogen-phosphates-potassium–calcium, originated in this view, and the theory still dominates orthodox scientific agricultural thinking today. But it does Liebig an injustice. He himself expressed doubt as to whether the “N-P-K” theory should be applied to all soils. Deficiency symptoms were more apparent in soils poor in humus than in those amply supplied with it. The following quotation makes one suspect that Liebig was by no means the hardened materialist that his followers make him out to be. He wrote: “Inorganic forces breed only inorganic substances. Through a higher force at work in living bodies, of which inorganic forces are merely the servants, substances come into being which are endowed with vital qualities and totally different from the crystal.” And further: “The cosmic conditions necessary for the existence of plants are the warmth and light of the sun.” Rudolf Steiner gave the key to these “higher forces at work in living bodies and to these cosmic conditions.” He solved Liebig’s problem by refusing to stop short at the purely material aspects of plant-life. He went on, with characteristic spiritual courage and a complete lack of bias, to take the next step. (Steiner 2007:6)
STEINER, Rudolf. 2007. The Agriculture Course. (Trans.: George Adams) Shrewsbury: Wilding & Son Ltd.