Paraherbalists claim that products made by the metabolic processes of plants or animals possess an innate superiority over identical products synthesized in a chemical laboratory. The falsity of this claim was demonstrated as far back as 1828 when the German chemist Friedrich Wohler synthesized urea from inorganic materials. Wohler's synthetic urea was identical in every respect with the urea biosynthesized and excreted by animals or biosynthesized and accumulated by many species of higher fungi. Materials made from such plants are believed to be superior in some way to those produced by conventional agriculture. This belief is based on a complete misunderstanding of plant nutrition and physiology.
Plants require inorganic nutrients such as nitrogen, phosphorus and potassium for normal growth.
They obtain these elements from the soil and have no mechanism for distinguishing their original source. If adequate amounts are present, plants grow normally. If they are not, this does not occur. Pesticides are a slightly different matter. Appropriate safety limits have been established, and some pesticides have been banned.