Soil resistance ensures that crops do not suffer from disease as soon as a pathogen occurs in the soil. Soil resistance is enhanced by biological activity in the soil, but also by the availability of the right minerals. Just as in the cow's rumen, a healthy biology produces resistance and use of feed, i.e. minerals.
Biological resistance is created by the 'beneficial' soil life competing with pathogens for nutrients and space. Bacteria and fungi that are near the plant root digest the substances excreted by the root. The root exudates are quickly converted, which means pathogenic fungi do not have a chance to germinate. The physical room on and around the roots also plays an important role. If this room is fully occupied by beneficial organisms, the pathogen has no room for further development. Some beneficial fungi grow in the root itself, which means they protect the root against undesirable penetrants.
Specific groups of organisms can strengthen the biological resistance of the soil. For example fungi that catch nematodes, that live on pathogenic nematodes or predatory nematodes that need other nematodes as a source of food. There are beneficial organisms that excrete substances, such as antibiotics, and in doing so help to remove the pathogen. There are also large groups of organisms in the soil that excrete enzymes to their environment. Difficult to absorb organic compounds are decomposed and made suitable for digestion. These enzymes can also affect pathogenic fungi or nematodes.
In short, the environment where the crop grows determines how it feels and behaves.
Read here how we arrive at that optimum environment (+ practical example with a Kinsey-Albrecht analysis)