All fertilizers deployed to the soil will require microbial transformations to transform to a form that is assimilable by crops, hence the importance of soil micro-organisms (i.e. a living soil).

Below is an analogy of how fertilizers must be transformed before they can be assimilated:


Paddy, cannot be eaten.
Just like
Urea, cannot be assimilated


Paddy is converted to Raw Rice, but it cannot be eaten.
Just like
Urea, through microbial transformation, transformed to ammonia


Raw Rice is converted into Cooked Rice, before it can be eaten. Just like
Ammonia + water, is turned into Ammonium, and through microbial transformation, transformed into Nitrate