"The products that are harvested and serve as food for humans and animals largely derive from the soil's nutrients. Therefore, ultimately, every quantity of plant or animal food consumed by humans corresponds to nutrients removed from the soil...

... The role of fertilizers in production is indeed particularly significant, because fertilizers are by definition "substances" that contain nutrients, without which plants cannot grow adequately and produce products...

... Fertilization is quite a complex subject. It could be simpler if soils contained inert components that would not affect the added nutrients. However, the various existing components influence, and in different ways, the "behavior" of each of them, because each nutrient is characterized by its unique chemistry in the soil...

... Fertilization cannot in any case be done "randomly," or even based on empirical data, but must be done with "rules"...