After decontamination of soil with hot steam a quick reactivation with microorganisms takes place. At the beginning, harmful as well as beneficial organisms resettle. But beneficial bacteria and fungi find better conditions and gain a considerable head start. In general beneficial organisms will prevail. The quick revival can be traced back to many different reasons: Most important is low competitive pressure from other species as well as the availability of nutrients and other beneficial chemical substances which were dissolved by steaming.
The first wave of reactivation comes from heat resistant species e.g. spore forming bacteria. The effect of heat shock on the termination of latency is well known in particular for bacteria and fungi. Furthermore microorganisms from deeper areas which were untreated move up.
Furthermore germinable spores arrive by air, most of them come from fungi. In most of the cases a new barrier against the spread of pathogens is formed quickly and naturally.
In rare cases, pathogenic organisms may prevail after steaming due to unbeneficial circumstances, which can lead to enormous damage. In order to prevent the spread of pathogenic organisms it’s recommended to seed beneficial microorganisms into the soil right after steaming.