Artificial fertilisation
The prevailing assumption that plants primarily take up water-soluble ions is correct only for biologically inactive soils. Plants are forced to adopt this solution for want of an alternative. In the absence of soil life, plants are compelled to live on aqueous solutions. The plants' state of health and quality provide the ultimate answer to the question as to whether this form of nutrition provides for optimum development.
If a plant takes up nitrate as a solution, for example (as in the case of mineral nitrogen fertilisation), its build-up of protein will be disturbed. This results in reduced resistance to diseases.